The Bruins entered the season without the services of goalie Tim Thomas, the Conn Smythe Trophy winner during Boston's 2011 championship.

[13] Then on April 2, 2013, with about a month left in the lockout-shortened regular season, Boston acquired veteran Jaromir Jagr from the Dallas Stars.

In the first round of the playoffs, Boston rallied from a 4–1 third period deficit in Game 7 to defeat the Toronto Maple Leafs in overtime.

The Bruins then eliminated the New York Rangers in five games, and then swept the top seeded Pittsburgh Penguins in the Eastern Conference Final.

[15] The Blackhawks finished the regular season with an NHL-best 77 points, winning their second Presidents' Trophy in team history.

In the Western Conference Final, the Blackhawks defeated the defending Stanley Cup champion Los Angeles Kings in five games.

[17] In the overtime periods, the Blackhawks were penalized twice for too many men on the ice, but Boston was unable to score on those two ensuing power-plays.

The game finally ended at 12:08 of the third overtime period when Michal Rozsival's shot from the point deflected off of Bolland, then Andrew Shaw, and past Rask into the Boston net.

After a scoreless third period, Daniel Paille won the game for the Bruins at 13:48 of overtime; the Blackhawks' Brent Seabrook sent the puck around the end boards in the Chicago zone, but Brandon Bollig could not push it out to centre ice, allowing Adam McQuaid to steal the loose puck and feed it to Tyler Seguin, who then passed it to Paille.

Jonathan Toews deflected Michal Rozsival's shot into the Boston net at 6:48 to give the Blackhawks a 2–1 lead.

At 09:51 of overtime, Brent Seabrook scored from the point through traffic to give the Blackhawks a 6–5 victory in game four to even the series at 2.

Boston's Zdeno Chara cut the score to 2–1 at 03:40 of the third period, but Chicago goalie Corey Crawford stopped 24 of 25 Bruins shots, and Dave Bolland added an empty net goal in the waning seconds of the game.

However, Chicago would fight back in the second period, as Blackhawks captain Jonathan Toews scored on a breakaway while shorthanded to tie the game (Toews' goal would be recorded as an even strength goal, as it entered the net just after Andrew Shaw's penalty expired).

With the Bruins clinging onto a 2–1 lead late in the third period, the Blackhawks pulled goalie Corey Crawford for the extra attacker.

This resulted in Bryan Bickell scoring the game-tying goal with 76 seconds remaining in the game on a feed from Jonathan Toews.

[27] Bolland's goal at 19:01 of the third period broke the record for the latest Stanley Cup game-winner scored in regulation.