BOSTON (AP) -- The Chicago Blackhawks kept taking the lead until there were no more chances for Boston to come back and tie it.
Brent Seabrook's slap shot beat Tuukka Rask with 9:51 gone in overtime and the Blackhawks beat the Bruins 6-5 on Wednesday night to send the Stanley Cup finals back to Chicago tied at two games apiece.
Game 5 of the best-of-seven series will be Saturday night, with Game 6 back in Boston on Monday.
Patrick Kane had a goal and an assist for the Blackhawks, who had only scored five goals total in the first three games of the series and hadn't gotten the puck past Rask in more than 129 minutes coming into Game 4. Bryan Bickell and Michal Rozsival had two assists apiece, and Corey Crawford made 28 saves for Chicago.
Patrice Bergeron scored twice, and Zdeno Chara and Jaromir Jagr each had two assists for Boston, which had won 11 of its previous 13 playoff games. Rask made 41 saves but he was screened on the game-winner, which quickly quieted the building where Boston had earned a dominating, 2-0 victory two nights earlier.
"One of things we have talked about, get pucks to the net," said Seabrook, a defenseman who also had the overtime goal in Game 7 of the Western Conference semifinals. "I just tried getting it on net, we had a great screen in front. ... It just found a way."
It was the third overtime game in the finals, but it bore little resemblance to the three tightly contested games that opened the series. The teams combined for five goals in the second period - as many as in Games 2 and 3 combined - as Chicago repeatedly sprinted into the lead only to have Boston come back and tie it.
The Blackhawks led 1-0, 4-2 and 5-4, but each time the Bruins evened it up, the last just 55 seconds after Chicago took the lead when Johnny Boychuk slapped it over a sliding Johnny Oduya with 7:46 left in regulation. Boychuk, who had never scored more than five goals in a season, has six in the postseason.
The overtime was even until the Bruins failed to clear the zone and the puck got to Seabrook at the right point. What seemed like a harmless shot found the back of the net, and the Blackhawks followed with a subdued celebration at the end of another long night.
"Both teams are so great defensively. Both have great goalies," Seabrook said. "I don't know; it was one of those games. They got some goals on the power play, we got some bounces. It was nice to get some past Tuukka."
The Bruins had won 11 of their last 13 games and trailed for under 60 minutes, total, of the almost 900 minutes they had played in the postseason. But the Blackhawks came out strong early in this one, recording the first seven shots and taking a 1-0 lead on a short-handed goal when Oduya was off for interference early in the first period.
Brandon Saad picked Tyler Seguin clean in the defensive zone and brought the puck down the ice before flipping it across to Michal Handzus, who rattled it in off the post to make it 1-0. The Bruins tied it on the power play when Andrew Ference kept the puck in at the blue line, and Rich Peverley finished it off with a wrist shot.
But it was in the second period that the teams really opened things up.
Jonathan Toews came around the back of the net and tipped in Rozsival's shot to put the Blackhawks back in the lead with 6 1/2 minutes gone. Just over two minutes later, Chicago took its first two-goal lead of the series when Rask stopped Bickell's shot but left the rebound for Kane; Rask was too far to his left to get back in front of the second chance that Kane converted to make it 3-1.
It stayed that way for six minutes more before Milan Lucic deflected Chara's shot into Crawford and then put back his own rebound to make it a one-goal game. Forty-nine seconds later, Kruger stuck with the puck until he had poked it past Rask and into the net to make it 4-2.
That's when Boston got some luck.
Chara's shot from the center of the blue line deflected off Crawford's left shoulder and over the net, where it hit the back wall, bounced back onto the top of the net and landing in the slot, right in front of Bergeron. He chipped it in to make it 4-3.
With under one minute left in the second, Kelly deflected a pass just wide of a net that was so open that the horn went off even though the referee emphatically and correctly signaled no goal. The Bruins continued to pressure Crawford, but Chicago made it through the period with a one-goal lead.
Patrick Sharp gave Chicago a 5-4 lead with 8:41 left in regulation - on an assist from Marian Hossa, who missed Game 3 with an undisclosed injury - but it lasted only 55 seconds before Boychuk tied it.
Notes: Bruins Hall of Famer Bobby Orr, who also played briefly for Chicago, was in the crowd, waving a yellow towel in support of the Bruins. ... Boston killed 29 consecutive penalties dating to Game 5 of the Eastern Conference semifinals, including the first 13 Chicago opportunities of the finals. ... The Blackhawks had the first seven shots of the game despite a penalty that left them short-handed. ... Jagr assisted on both goals by Bergeron, giving the 1999 NHL MVP 199 career postseason points. He is fifth all-time. ... Midway through the first, Boston's Shawn Thornton hit the scoreboard when he lofted the puck out of the zone.