Let's take a look at the 49ers final post-game grades and evaluations.
Alex Smith: B
Smith looked good, as usual this preseason, but was smacked around a bit due to extremely sub-par play from the starters on the offensive line.
Nonetheless, he hooked up with his favorite target, TE Vernon Davis, for a 44-yard TD and finished with a 142.3 passer rating on the day. He took every offensive snap in the first half, except the final one.
Colin Kaepernick: A-
Kaepernick surprisingly showed some development in this game, firing a strike to the sideline on a broken play to extend one drive, and putting a perfectly placed ball into Kyle Williams chest that created a 46-yard pass play as well.
"Kapper" threw for 80 yards and was a perfect 4 for 4 passing. He ran for 11 yards on two attempts as well.
Scott Tolzien: B
Tolzien came out firing after initially replacing Kaepernick, but San Fran receivers dropped two of his passes and the QB wound up 1 for 4 with a 16-yarder to WR Brett Swain serving as his only completion.
The important thing for Tolzien is that he came out as the team's third QB, a promising sign for his future with the 49ers.
Josh Johnson: C
There isn't much to Johnson's grade, as he only came in for one drive and didn't get many snaps. He made a nice play moving the chains with his feet, but overthrew TE Garrett Celek on a would-be fourth quarter TD pass.
Frank Gore: C
Assessing a grade to the 49ers all-time leading rusher really isn't fair. He carried the ball twice and was given no room to get anything going on either play.
Kendall Hunter: B
Hunter ran hard, as usual, but wasn't given much more open space to roam than Gore. He did break off a nice 11-yard run, and had another decent scamper that was called back.
Anthony Dixon: A-
Dixon needed to run for his life in this game to have any chance of surviving the looming roster cuts, and that's just what he did. Equipped with more sufficient run blocking in the second half, Dixon rumbled 26 yards into the end zone on a short-yardage run and totaled 58 yards on 13 attempts overall.
Boobie's biggest weakness was probably that his helmet came flying off on two different occasions. Scary.
Rock Cartwright: C+
Cartwright had a nice 27-yard run featuring solid ball protection before going down, but gained just five yards on seven other tries. He was largely a victim of sub-par run blocking when he got the call.
Michael Crabtree: A-
Crabs made three grabs on the night, all coming from Alex Smith and totaling 21 yards. He showed nice hands on a sideline catch to move the chains early on and converted on all three targets.
Randy Moss: C
Moss didn't serve much of a purpose in this game, though it was nice to see him draw three defenders on an Alex Smith deep ball. The pass was overthrown, but it's evident that Moss can still draw some serious attention on the field.
A.J. Jenkins: B
Jenkins made a nice grab on a low Kaepernick throw just shy of the goal-line, but wasn't much of a factor, otherwise. Did have a nice 9-yard run on an end around to open the second half.
Brett Swain: C+
Swain made good on a perfect pass from Tolzien late in the game, his only target of the day. Unfortunately, the WR has little-to-no shot of making the squad.
Undrafted Free Agent Rookies Chris Owusu, Nathan Palmer and Brian Tyms: D
The youngsters didn't receive so much as a single target in this game, and saw little action outside of special teams.
Vernon Davis: A
One target, one 44-yard TD catch. Vernon was probably looking to end his preseason on a good note after dropping a perfectly-placed throw from Alex in the game against Houston.
The freakishly talented tight end took this beautifully thrown ball to the end zone and reminded fans that he's ready to build on a heroic performance in last year's two playoff games.
Konrad Reuland: B+
"The Garbage Man" sucked in his only target, a frozen rope from Kaepernick that went for 16 yards. It'll be interesting to see if Reuland can find a spot on the 53-man roster, or more likely, the practice squad.
Garrett Celek: D
Celek dropped a strike from Tolzien, and continued to struggle with his hands this preseason. He fumbled last week, but did recover the ball. In three targets on Sunday, he couldn't haul in a single pass.
Joe Staley, Mike Iupati, Jonathan Goodwin, Alex Boone and Anthony Davis: D
This group played the entire first half together (17 snaps) and potentially raised some concerns with their sub-par performance as a unit.
Staley allowed DE Elvis Dumervil into the backfield unblocked for a sack of Alex, and the interior could not muster any sort of momentum in the run game. 49er running backs consistently failed to get out of the backfield, totaling a measly 13 yards on eight first half attempts.
The Reserves: B
The offense looked exactly the opposite of its first half form, and much of the credit goes to the 49ers backup offensive linemen.
Newcomer Leonard Davis looked solid, as he and the rest of the second half O-line consistently created gaping holes for Dixon and Cartwright to run through. There were some breakdowns in pass blocking, but not nearly as bad as the first half.
Justin Smith, Isaac Sopoaga and Ray McDonald: D
This grade may initially seem harsh, but this was hardly the typical performance you'll see from the starters on the D-line.
The trio failed to get much of any pressure on Manning, and didn't look themselves in run defense, either.
The Backups: B+
Ricky-Jean Francois, Will Tukuafu and Demarcus Dobbs fared much better than the starting unit in this game. Tukuafu recorded a sack and forced fumble, and Dobbs was in the backfield on numerous occasions pressuring the Broncos backup QB's.
The Broncos only managed 58 yards of offense in the second half, and this group deserved much of the credit.
Ahmad Brooks, Parys Haralson: C
Brooks made a nice backfield stop on a Broncos runner and Haralson put a nice lick on Manning, but no member of the 49er starting defense (that played) is going to receive a positive grade after this performance.
Though it was just a tuneup and Haralson isn't projected as a starter once injured OLB Aldon Smith returns from a bruised hip, the pass rush was nowhere to be found and coverage was even worse for both of the first-unit OLB's.
Patrick Willis, Larry Grant: C
Grant recorded nine tackles on the night, but was burned badly by Manning while trying to cover a running back. Many of his stops were after the ball-carrier had already gained substantial yardage.
Willis appeared uncharacteristically ineffective and wasn't playing with the same passion that 49ers fans will undoubtedly see once the regular season kicks off.
Michael Wilhoite, Eric Bakhtiari, Kenny Rowe: B+
Bakhtiari, a preseason standout thus far, suffered a concussion early on and missed the rest of the game. Inside linebackers Wilhoite and Rowe impressed, though, with both recording tackles for loss, including a sack for Rowe to kill a Broncos' drive late in the final quarter.
Carlos Rogers, Tarell Brown: D
I know the 49ers weren't exactly game-planning against Peyton and the Broncos starting offense, but it was disappointing to see him move down the field so effortlessly. Rogers had tight coverage a couple times, but one play likely would've resulted in pass interference if the regular referees were in action.
Perrish Cox: B
With Chris Culliver missing due to a knee injury, Cox saw plenty of action on Sunday. He recorded his second interception in as many games this preseason, taking a poorly-thrown Caleb Hanie pass and returning it 21 yards inside the Denver 20-yard line.
Cox did struggle to wrap up ball-carriers, however, as did many 49ers defenders in this game.
Dashon Goldson, Donte Whitner: C
A quiet night for these two, who were unable to make much of an impact in the snaps they did see. The absence of an effective pass-rush up front didn't help their cause.
Tramaine Brock: D-
Brock recorded six tackles, but it was mainly because he failed to successfully cover Broncos' receivers anytime the ball came his way. A less than desirable performance for a projected No. 5 CB who may end up on the wrong side of the upcoming roster cuts.
Trenton Robinson, Michael Thomas: C
Robinson recorded three tackles, and I didn't see any major mistakes from him. Thomas nearly got his head ripped off by a Knowshon Moreno stiff arm, but still managed to bring him down.
David Akers: A
A familiar sight for 49ers fans, Akers booted five field goals on the day, converting on every attempt. The kicks went for 21, 32, 33, 44 and 45 yards, giving the All-Pro kicker plenty of warm-up tries heading into the regular season.
Andy Lee: A
Preseason or not, Andy Lee is as steady as they come.
Steadily amazing, that is.
Lee punted three times on the day, averaging 59.3 yards on those attempts. His long was a 65-yarder. Simply put, no one does it better.
Return Game: B-
Neither team had a single kick return, thanks to the thin air at Mile High and the fact that kickers are already teeing it up at the 35-yard line. Kyle Williams successfully hauled in three punts and gained 30 yards on the run-backs. Ted Ginn. Jr fielded the initial punt, but called for a fair catch. He left the game just after the second half began when an opponent fell on top of his leg, twisting his ankle.
Kickoff/Punt Coverage: A-
The Broncos attempted to return just two punts, and gained only two yards on those attempts. The coverage was sound and Lee's booming punts made life extremely difficult for the awaiting return men.
Coaching Staff: C
Being that it's preseason and all, it's never easy to judge the performance of a coaching staff in exhibition play.
Harbaugh and his staff were clearly more concerned with assessing individual performances than game-planning for their opponent.
Kudos to Harbaugh for sending the reserve offense out firing in the second half and leading a comeback win, but the sloppiness we saw in the first half was a forgettable experience.
I don't expect Harbaugh to be too worried, but lackluster play-calling led to field goal attempts in the red zone, and there was an all around lack of organization from the offense early in the game. The 49ers were called for a delay of game after a timeout, which was odd. It's possible the replacement refs made matters worse by not alerting Alex Smith that the play clock had started ticking down, but it was sloppy, nonetheless.