Rory McIlroy at US Open 2015: Sunday Leaderboard Score and Twitter Reaction

After three frustrating rounds, Rory McIlroy finally tamed Chambers Bay. Now he'll sit in the clubhouse and see whether it was too little, too late.

McIlroy fired a four-under six, tying the best overall score in Round 4 and putting himself two shots free of anyone else who has finished his round. The world No. 1 will spend the rest of his evening watching Branden Grace, Dustin Johnson, Jason Day and Jordan Spieth, who comprise the day's final groups and have quite a bit time remaining in their respective rounds.

For now, McIlroy can bask in the glory of finally cracking the Chambers Bay code.

Sitting four over after failing to mount a third-round charge, McIlroy was considered all but an afterthought coming into Sunday. He had barely scraped by to make the weekend after going 72-72 before coming out and missing opportunity after opportunity in his third round. Even McIlroy seemed resigned to the fact he was out of contention.

“[I’ll] keep trying and keep going, give it a good go [Sunday]," McIlroy said after the round, per Mark Cannizzaro of the New York Post. "I’m glad my name is on the trophy at least once and I’ll try to make it twice at some point.’’

Early on, it looked exactly like McIlroy would merely be giving it the old college try. A birdie on the par-four second was his only under-par score for the first six holes, as the missed opportunities that plagued his third round carried over. He came within inches of birdieing the third and missed two more opportunities on No. 4 and No. 6.

But a sterling stretch of play starting on No. 7 changed the course of McIlroy's round and thrust him into the leaderboard conversation. He nailed a 14-foot birdie putt on the seventh and took advantage of one of the course's two par fives at the eighth, making the turn at 32. Those back-to-back birdies began a stretch of four in six holes capped off by an insane 72-foot birdie putt at No. 13 that sent the entire state of Washington to its feet.

On the day, McIlroy needed 30 putts, his best of the week. The greens have been a source of nonstop discontent among players all week, with Sunday seeing some totally lose their cool amid the frustration. McIlroy's putter probably cost him five or six strokes by the end of the week, but he's taken a more diplomatic approach with his public comments.

"They are what they are," McIlroy said Saturday, per Christine Brennan of USA Today. "Everyone has to putt on them. It's all mental. Some guys embrace it more than others, and that's really the way it is. It is disappointing that (the greens) are not in a bit better shape."

NFL Network's Rich Eisen thought McIlroy was headed for the top of the leaderboard following the putt. 

Unfortunately for the world No. 1, his momentum began fading down the stretch. He carded his first bogey of the day at No. 15 after hitting his tee shot into the rough and failing to get up and down. Birdie putts on Nos. 16 and 17 missed, with the latter turning into a frustrating three-putt that ended any hope he had of making up the deficit, as noted by Fox Sports' Shane Bacon:

Given the way the leaders have held strong throughout the day, it was always unlikely that McIlroy would wind up capturing his second U.S. Open. It was nonetheless a disappointing end to what was by far the most exciting 18 holes thus far Sunday.

Depending on how the swath of players remaining on the course performs, McIlroy should wind up with his second top 10 in as many majors.

The Northern Irishman has not placed worse than 11th in a PGA-sanctioned event since February. He has reached an almost Woodsian level of consistency wherein even his worst possible performance—and McIlroy's putting was at its worst at certain points this week—is still better than nearly everyone's best.

Ted S. Warren/Associated Press

That just hasn't translated to wins in high-profile tournaments yet in 2015. He's stayed in the fringes of contention in each big event (Masters Tournament, The Players Championship and U.S. Open) but is still missing that one triumph that will put him in Player of the Year consideration. 

Up next will be The Open Championship at St. Andrews, perhaps the most storied links course in the sport's history. That trip will undoubtedly bring back memories of McIlroy's last Open at the Old Course, which saw him post a nine-under 63 before ruining his chances with a second-round 80. At the time, it was viewed as a disappointing missed opportunity as the young star ascended up the world rankings.

Golf writer Ryan Ballengee is already predicting a win:

Five years later and now unquestionably the world's best golfer, McIlroy will look to exorcise his demons and re-establish his dominance.