AMERICAN LEAGUE Yankees' Clemens takes the mound against rival Sox

New York's ace is two wins away from No. 300.
BOSTON (AP) -- A day after Pedro Martinez missed a start with an injured back muscle, former Red Sox ace Roger Clemens will try for win No. 299.
If Clemens wins, he'll knock his former team out of a tie for first place in the AL East, where the Red Sox find themselves today after rallying for a 10-7 win over the Yankees on Tuesday night.
Tonight's game "against Roger will be even bigger than the first two" of the series, Boston's Jeremy Giambi said.
"He's a great pitcher and first place and this series are on the line."
If Clemens wins, he'd be lined up to get his 300th win next week against Boston in Yankee Stadium.
"I think every time Roger pitches, everybody expects big things," Yankees manager Joe Torre said. "Hopefully, he can win a series for us. We haven't done that for a while."
Stumbling
The Yankees have lost their last three series. Tuesday's loss, thanks to a five-run seventh inning by Boston against Jose Contreras (1-1), was their seventh in nine games.
But they seemed to have a good chance when Martinez was scratched from his start about four hours before the game. An MRI exam during the game showed a mild strain in the latissimus dorsi muscle below his right shoulder blade. He is day to day.
"You get in a little better mood" when you find out he's not pitching, Torre said. "But everything is not based on what they do, but what we do."
Bruce Chen, who made just three relief appearances since being claimed off waivers from Houston on May 7, filled in.
He started off poorly, allowing a homer by Alfonso Soriano and a single by Derek Jeter -- the first two batters. But he allowed just two other hits and left with a 4-3 lead after four innings.
"He kept us in the game," Boston catcher Jason Varitek said. "This team doesn't panic. It's nice to do it again and again because it builds our confidence."
Rallying Red Sox
The Red Sox (28-17) have 13 comeback wins and nine victories when trailing after six innings.
"It says a whole lot about the character of this team," Boston manager Grady Little said.
"They knew what they were up against today."
After former Yankee Ramiro Mendoza allowed three runs in the fifth, Contreras relieved Jeff Weaver with New York ahead 6-5 in the sixth and got two batters to hit into a double play and strike out.
But he faced seven batters in the seventh -- allowing three hits, three walks and a sacrifice fly -- as Boston took a 10-6 lead.
"I'm going to focus on the positive" in the sixth, Contreras said through an interpreter. "I felt a lot more comfortable after having the results I had previously that everyone's aware of."
Boston loaded the bases with no outs in the seventh on a walk to Todd Walker, Nomar Garciaparra's second double of the game -- as he extended his hitting streak to a major-league best 21 games this season -- and a walk to Manny Ramirez.
David Ortiz put Boston ahead to stay with a double and Trot Nixon hit a sacrifice fly for an 8-6 lead.
Jorge Posada hit his 11th homer in the eighth off Mike Timlin, but Alan Embree (3-1) pitched a perfect seventh, and Brandon Lyon struck out all three batters he faced in the ninth for his sixth save in six opportunities.