PHILADELPHIA -- Chase Utley feels at ease in the playoff push.
"I think it's pretty relaxed around here," Utley said. "We're having a great time. We're playing great baseball so I think that helps. I don't feel any pressure around here."
Roger Clemens was long gone by the time this one ended, forced out of his 15th start of the season with a strained right groin. The Astros said the 44-year-old right-hander is day to day.
After both teams wasted opportunities to win late in the game, Utley hit his 25th homer to right off Dave Borkowski (1-2). The second baseman was mobbed by his teammates and helped the Phillies snap a 12-game losing streak to Houston that dated back to May 18, 2003.
"I guess that's how you beat them," Phillies manager Charlie Manuel said.
Rick White (3-1) pitched a scoreless 10th for the win, retiring the final two batters he faced to leave a runner stranded on third. The Phillies remained 1½ games behind San Diego, the NL wild-card leader.
Clemens, 6-4 with a 2.27 ERA, gave up one run, struck out six and walked two. Clemens felt something on the next-to-last pitch he threw in the fifth inning.
"I feel better. The tenderness I felt has relaxed," he said. "I'm still on for Saturday unless something changes. We'll give it a chance to heal and see what happens."
Howard earned some surprising respect leading off the ninth when Chad Qualls intentionally walked him. But Qualls worked out of a bases loaded, one-out jam, striking out pinch-hitter David Dellucci and retiring pinch-hitter Jose Hernandez on a pop-up to first base to send the game into extra innings.
"We're not going to let him hit one out of the park," Astros manager Phil Garner said.
It was the second consecutive extra-inning game for the Phillies, who lost to Atlanta in 11 innings in the second game of Sunday's doubleheader. Philadelphia also played back-to-back doubleheaders over the weekend, and came right back for a 3:05 p.m. ET start Monday.
Howard's 53rd homer of the season off Russ Springer in the sixth knocked off the facing of the second deck in right field. Much like when he homered in his first three at-bats against Atlanta in the first game of a doubleheader on Sunday, Howard earned a standing ovation and chants of "M-V-P!" as he rounded the bases.
Howard also extended his hitting streak to 14 games.
"Hopefully this win can set the tone for the rest of the series," Howard said. "We'll try and ride it out down the stretch and try and make the playoffs."
Cole Hamels was absolutely fantastic again, retiring the first 17 batters and pitching like the future ace the Phillies expect him to be. The hard-throwing lefty was working the corners and getting strikes on fastballs, then finishing batters off with offspeed pitches.
He struck out the side in the fifth, with Jason Lane thinking he walked, only to get racked up on the slow stuff. As Hamels walked off the mound, the fans in the first few rows stood and applauded.
Hamels, who singled off Clemens, tried blocking out the packed crowd and The Rocket's presence.
"It's one of those things you think about before the game, but when you get in the moment of stepping between the lines, it disappears," Hamels said.
Hamels seemed poised to close out the Astros and record his eighth win until Aubrey Huff hit a solo shot leading off the eighth, tying the score at 2-2.
"If we can't get to .500, we can't even put 'wild card' in our vocabulary," Garner said.
The Phillies touched Clemens for a run in the fourth, but missed their chance for a big inning. Clemens fanned Pat Burrell on a called strike at the knees with the bases loaded. He hit Jeff Conine in the left shoulder to make it 1-0, but Chris Coste grounded into a double play to end the threat.
Jimerson pinch hit for Clemens with two outs in the sixth inning and broke up Hamels' perfect game with a home run in his first major league at-bat. Jimerson hit a shot to deep center field near Ashburn Alley, the outfield entertainment area.
- The Phillies recalled LHP Matt Smith from Class A Clearwater and he pitched a scoreless ninth. Smith was acquired from the Yankees as part of the Bobby Abreu deal. Smith made two appearances at Clearwater and struck out all six batters he faced.
- The game was a sellout with a crowd of 44,674, including more than 10,000 tickets sold on Monday.