"I used to say this when I was in Oakland: I actually like close games," Mulder said. "It keeps me focused.
"Sometimes when the team isn't scoring runs it's easier to focus because you know one mistake can cost you the game."
Mulder (5-1) won his third straight start and had two of the Cardinals' four hits in seven innings against Trachsel, with singles in the fifth and seventh. Scott Rolen doubled in a run in the sixth inning.
Mulder departed after the Mets loaded the bases with one out in the ninth. With speedster Jose Reyes at third, Isringhausen struck out David Wright, then got Cliff Floyd to ground out to first for his 12th save in 14 chances.
"Just a lazy fly ball in the outfield, Reyes is going to score from third," Isringhausen said. "You know that. All I was trying to do was keep the ball on the ground, and hopefully get a double play."
Rolen was only 4-for-28 in the first eight games of a nine-game homestand before his two-out double to the gap in left-center off Trachsel (2-4) broke up a scoreless game. Albert Pujols drew a one-out walk and scored without a play to give him 40 runs in the first 40 games.
"It was a good pitch," Trachsel said. "I saw it on replay and it was even better than I thought it was.
"He's a good RBI guy, tip your hat to him."
Pujols, who was 0-for-3 a day after taking a nasty spill while chasing a foul pop that landed him flat on his back, is the first player to reach that run total so quickly since Floyd and Todd Helton in 2001. Pujols wore a guard on his left leg after a fouling a ball off his shin in another mishap on Tuesday.
The Cardinals are 16-5 against the Mets the last four seasons and they're 17-7 at new Busch Stadium, rebounding after losing the last two.
"We had our shot, no other way to look at it," Mets manager Willie Randolph said. "At the end of the game we had the bases loaded with our best hitters up there.
"Good pitching all the way around."
Wright had his second straight two-hit game for the Mets off Mulder, who struck out five and walked two. The Mets threatened in the fifth with runners on first and third with one out, started by Wright's leadoff double, but Kaz Matsui popped out and Trachsel flied out to center on a 3-2 pitch after being ahead 3-0 in the count.
Mulder worked past the sixth for the first time in four starts this month and is 4-0 at home with a 2.72 ERA. He leads left-handers with 53 victories the last four seasons, one more than the Twins' Johan Santana.
This was only his second start without giving up a homer. He's given up eight to tie for the staff high with Jason Marquis.
"Well, I pitched a little better, too," Mulder said. "I felt comfortable out there. It wasn't one thing, I was just making better pitches."
Trachsel allowed one run and four hits in his longest outing of the year. Trachsel, who struck out two and walked three, has lost three of his last four starts.
The Mets haven't scored a run for him the last two games, also losing 2-0 in a rain-shortened five-inning game May 11 at Philadelphia.
- Trachsel retired the side in order in the first inning for the first time all season, then followed with a perfect second. He had no perfect innings in his three previous starts.
- Trachsel is 9-9 for his career against the Cardinals, but hasn't beaten them since Sept. 22, 1999, when he was with the Cubs.
- Mulder has four career two-hit games and is 5-for-18 (.278) this season after batting .145 last year.
- The Cardinals' last 1-0 victory was April 23, 2005, in 10 innings, with Mulder outdueling the Astros' Roger Clemens.
- The Mets last 1-0 defeat was Sept. 19, 2004, at Pittsburgh, one of three 1-0 losses that season.