David Krejci's third goal gave the Bruins an overtime victory at Toronto.
The last two Stanley Cup winners were under intense pressure Wednesday night.
The Boston Bruins wanted to put a stranglehold on their series with the Maple Leafs in Toronto, while the Los Angeles Kings wanted to take the pivotal fifth game on the Blues' home ice.
Both teams accomplished their goals, as did the New York Rangers and the Anaheim Ducks.
Here are the biggest takeaways from the ninth night of action in the 2013 Stanley Cup playoffs.
The New York Rangers were a team that was hunting goals all season long.
More often than not, that hunt was unsuccessful The Rangers could be counted on for one or two goals in most games. Any more than that, and head coach John Tortorella would do a little dance behind the Rangers bench.
But as the Rangers came together following the trade deadline, they seemed to be a more complete team. They have been growing since early March and appear to have matured greatly even in the past two games.
Instead of getting a goal or two and holding on with Henrik Lundqvist in the net, the Rangers have scored four goals in back-to-back games.
In their Wednesday night 4-3 victory over the Caps in Game 4, Brad Richards, Carl Hagelin, Dan Girardi and Derek Stepan scored for New York.
Girardi and Stepan both scored when the game was on the line in the third period.
Late goals from the Rangers? It's reality, and they have evened up their series with the Caps at 2-2.
The Boston Bruins wanted to go home with a 3-1 lead in their series with the Toronto Maple Leafs.
Center David Krejci made that happen. He scored three goals against the Leafs in a 4-3 overtime victory, and his final goal at 13:06 was a thing of beauty.
Krejci took advantage of a reckless pinch by Toronto defenseman Dion Phaneuf and skated in on a 2-on-1 with left wing Milan Lucic.
The ever-patient Krejci made like William Walllace as he calmly held the puck on his forehand for what seemed like a lifetime, before calmly wristing the puck through Toronto goalie James Reimer.
The goal was his fifth of the series, and he has scored 10 points in the four playoff games. Krejci leads all playoff scorers in goals and points.
Braden Holtby is the backbone behind the Washington Capitals' defense.
The Capitals know that if they make a mistake at any point in a playoff game, Holtby has the ability to bail them out.
Prior to Wednesday night's 4-3 loss to the New York Rangers, Holtby had never lost two consecutive playoff games.
Holtby was coming off a 4-3 loss in Game 3 and is usually at his best off of a defeat. However, the Rangers appeared to figure him out, scoring on four of 34 shots.
That's merely an .882 save percentage, not good enough for a goalie who has designs on taking the Caps a long way.
When you face the Boston Bruins in any playoff series, you have to find a way to get the best of center Patrice Bergeron and defenseman Zdeno Chara if you are going to have a legitimate chance to win.
Bergeron is one of the best all-around players in the league, while Chara is the huge defenseman who can shut down the best scorers in the game.
Chara's primary job in this playoff series against the Toronto Maple Leafs is to hold high-scoring Phil Kessel in check.
In the Bruins' 4-3 overtime victory Wednesday night, Kessel was limited to one assist.
However, Chara did not stop there. He was an offensive force in Game 4, registering four assists in the game. He started the play that led to David Krejci's game-winner, as he got the puck to Nathan Horton, who was able to chip it to Krejci.
Chara's four-point game was the first for the Bruins in the postseason since Tyler Seguin had two goals and two assists for the Bruins in 2011 against the Tampa Bay Lightning.
The constant factor in the Los Angeles Kings-St. Louis Blues first-round series is the hard-hitting and demanding physical play.
Going into the fifth game in St. Louis, the home team had won all four of the games in the series.
The defending Stanley Cup champion Kings knew that if they were going to stay alive and make a run at a second consecutive Stanley Cup, they would have to beat the Blues on the road in either the pivotal fifth or decisive seventh game.
They decided to assert themselves in Game Five. After the two sides battled on even terms for three periods, the Kings won the game in overtime when Anze Kopitar started a rush up the ice and passed to Justin Williams, who spotted defenseman Slava Voynov and put a fine pass on his forehand.
Voynov may not be the most talented offensive player—he had two playoff goals in his previous 23 postseason games—but he slid his shot by St. Louis goalie Brian Elliott to give the Kings a 3-2 win in the extra session.
The Kings have a chance to put the Blues away in six games if they can take advantage of their home ice at the Staples Center on Friday night.
The St. Louis Blues play every game hard. That's been their signature since Ken Hitchcock became head coach early in the 2011-12 season.
Trailing 2-1 late in the third period, the Blues were pressing for the tying goal. They pulled goalie Brian Elliott in the final minute, and Hitchcock called timeout to give his players a breather and draw up a final play.
As the Blues got control of the puck, David Backes and Jaden Schwartz sent the puck back to Alex Pietrangelo. The Kings had a phalanx of players in front of Pietrangelo at the right point. A tiny lane opened as Pietrangelo drifted toward the middle of the offensive zone. He sent a wrister towards goal, and Kings goalie Jonathan Quick never saw it.
The Blues had tied the game with a spectacular seeing-eye shot by Pietrangelo that sent the game into overtime.
While the Blues would lose in overtime, it was the kind of all-in execution that the Blues have been noted for under Hitchcock.
The Anaheim Ducks figure they had one coming to them.
One overtime win, that is.
When the Detroit Red Wings and Anaheim Ducks went at it in Game 5, the two teams had split their first four games.
However, the Ducks figured they were the better team. Their two victories had been by a combined six goals, while the Red Wings' wins both came in overtime.
This time, the Ducks came away with the overtime goal—and they didn't take long to do it. Nick Bonino scored less than two minutes into the extra session, getting a little OT revenge for the Ducks.
Anaheim can close out the series on Friday night if they can get a win at the Joe Louis Arena in Detroit.