The Rocket shut down his original team, allowing only two hits and outpitching an ace 18 years younger than him in the New York Yankees' 4-3 victory over the Red Sox on Wednesday night.
"I was trying to be as stingy as possible," Clemens said. "It's going to be a grind for me. I'm asking my body to be 25 right now."
Alex Rodriguez hit his major league-leading 44th home run and the Yankees got another big hit from Johnny Damon to earn their second consecutive win in the series. New York trimmed Boston's cushion to six games in the AL East and moved within a percentage point of Seattle for the wild-card lead.
"It's nice when things matter," Clemens said. "We've still got a lot of work to do."
Clemens (6-5) held the Red Sox hitless until David Ortiz's upper-deck homer with one out in the sixth. He worked around a season-high five walks and improved to 9-5 with a 3.73 ERA in his career against Boston, a team he last faced in Game 7 of the 2003 AL championship series.
"Nothing around the plate to hit, always on the corners, changed speeds pretty well," Boston's Dustin Pedroia said. "We had guys on, we just didn't get the big hit."
The Yankees tied the season series 7-all after losing the first four meetings. The teams play four more times this year, including Thursday afternoon. New York will go for a series sweep when 15-game winner Chien-Ming Wang faces Boston's Curt Schilling.
"Everything's in our grasp -- the wild card and the division," Yankees reliever Kyle Farnsworth said.
Kevin Youkilis also homered for the Red Sox, who played without injured star Manny Ramirez. The slugger sat out with a strained muscle on his left side and probably will be sidelined for several days.
"I don't know. Maybe a week?" Ramirez said.
Youkilis' two-run shot off Farnsworth in the eighth cut it to 4-3. Rivera entered with a runner on first and got four straight outs for his 22nd save in 25 chances. It was his second in two nights against Boston, often a personal nemesis.
The 45-year-old Clemens, who earned 192 of his 354 career wins with Boston from 1984-96, struck out two and improved to 3-0 in his last four starts.
"It's still fun for him," Yankees manager Joe Torre said. "It's a piece of history you're watching out there."
Rodriguez hit a solo homer off Beckett (16-6) in the seventh to make it 4-1, then came out for a curtain call. A-Rod's 508th home run tied Toronto's Frank Thomas for 20th on the career list.
"Stupid pitch, stupid spot," said Beckett, who threw a shutout at Yankee Stadium to clinch the 2003 World Series for Florida.
The 27-year-old Beckett, a fellow Texas fastballer who grew up idolizing Clemens, allowed four runs over 6 2-3 innings in their first career matchup.
"I wasn't facing him. My guys were facing him," Beckett said.
The right-hander, who had won three straight decisions, was looking for his major league-best 17th win, which would set a career high. He dropped to 9-2 in 11 starts on the road this year.
"A guy who left every ounce of what he had out there," Boston manager Terry Francona said. "A lot of hits and a refusal to give in."
No. 9 batter Melky Cabrera had three singles for the Yankees, who outhit the Red Sox 14-4.
Ortiz's 25th homer cut New York's lead to 3-1. Second baseman Robinson Cano made an athletic, twirling play to retire Mike Lowell on a grounder that deflected off Clemens. With runners at the corners, Clemens retired Jason Varitek on an inning-ending grounder.
"You marvel at what he's able to do on the mound," Rodriguez said.
Cabrera's two-out RBI single put the Yankees ahead in the second. Cabrera moved up on a wild pitch and Damon followed with a two-run single, skillfully stroking a full-count fastball through the hole on the left side.
Damon, who hit a tiebreaking homer in Tuesday night's 5-3 victory, is batting .344 since July 21 with four home runs and 23 RBI.
"Unless he plays, we don't win," Rodriguez said. "Johnny to me I think is the most important part of our offense."
- The 13 hits allowed by Beckett were the most off a Boston pitcher since Curt Schilling also gave up 13 on April 22, 2004, at Toronto.
- New York is 14-2 when Damon starts in left field.
- The farthest the Yankees were out of the wild card this season was 9 1/2 games through games of July 7.
- The sellout crowd of 54,986 included Paul McCartney and actor Kevin Bacon.
- Farnsworth didn't allow a run in his previous seven appearances, giving up only one hit.
- The Yankees are 31-11 in their last 42 home games.