FOXBOROUGH, Mass. -- Shalrie Joseph scored in the 75th minute to lift the New England Revolution to a 2-1 victory against the Chicago Fire on Sunday in the opening game of their Eastern Conference semifinal series.

Chris Rolfe opened the scoring for Chicago in 17th minute, and Emmanuel Osei tied it for New England seconds before halftime.

The teams conclude the two-legged series at Toyota Park on Saturday.

"We didn't start particularly great early on," Revolution coach Steve Nicol said. "But we got the win that we wanted."

The Fire tested the Revolution defense early, as Brian McBride headed a pair of passes that went wide of the net just before the 10th minute.

The Fire finally capitalized when Marco Pappa went down the right side and sent a wide-angled shot that Revolution goalkeeper Matt Reis failed to smother. Rolfe captured it and scored to put Chicago ahead.

McBride nearly made it 2-0 only two minutes later when he took a pass from Pappa and rocketed a shot that beat Reis but clanked off the left post.

New England started to carry the play offensively after the 20th minute, with Jeff Larentowicz sending a pair of close shots as the Revolution kept the pressure on the Fire through 30 minutes.

One of Larentowicz's opportunities came in the 26th, when Chicago goalkeeper Jon Busch journeyed well off his line to challenge Joseph on a long ball. Busch fell down and Larentowicz had a clear shot at the unmanned goal, but sent a shot through that ricocheted off the far post.

"We didn't do much for the first 10 to 15 minutes -- we got frustrated," Nicol said. "But after that, we began to play loose."

The Revs continued to attack and Osei nearly recorded his first MLS goal in the 40th minute when his 25-yard shot skimmed off the near corner of the net.

Osei didn't have to wait long for another chance. Two minutes into extra time, Kenny Mansally delivered a free kick that Osei deflected past Busch for the tying goal.

The Fire battled back early in the second half and nearly went ahead when Pappa's long-distance shot hit the bar and bounced off the goal line in the 71st minute.

The Revolution quickly took advantage of their good fortune. Four minutes later, Larentowicz directed the ball toward Joseph, who fired it through to give his club the lead.

New England withstood Chicago's push for the tie in the final 15 minutes.