SAN DIEGO -- Albert Pujols homered and John Gall had a hit and scored twice in his major league debut as the St. Louis Cardinals beat San Diego 4-2 on Tuesday night in a matchup of division leaders, handing the Padres' their season-high eighth straight loss.
The punchless Padres fell to .500 (50-50) for the first time since May 4. San Diego was 14 games above .500 on May 31, when it completed the best month (22-6) in franchise history.
San Diego continues to lead Arizona by three games in the weak NL West despite going 17-31 since June 1.
Mark Mulder (12-5) won his fourth straight decision for the NL Central-leading Cardinals, who lost three of four to the Padres in St. Louis in early May. Woody Williams (5-7), who made four postseason starts for the Cardinals last year, took the loss.
A day after rejecting a trade to Baltimore for pitcher Sidney Ponson, San Diego's Phil Nevin made his first start at catcher since 1999 and batted cleanup. Nevin lost his starting job at first base because he was slumping at the plate.
Nevin received warm ovations when the starting lineups were introduced and when he came to bat in the first inning, drawing a walk. But he was booed after hitting into a force play to end the third inning, hitting into a double play to end the fifth and fouling out in the seventh. He finished 0-for-4 and flied out to left the game.
Xavier Nady, who replaced Nevin at first, went 3-for-3 with a walk and a run. The Padres stranded 10 runners and hit into three double plays.
Gall was called up from Triple-A Memphis to replace Larry Walker, who was put on the disabled list. He doubled in his first at-bat leading off the second, reaching when shortstop Khalil Greene couldn't make an over-the-shoulder catch in shallow left. He advanced on Mark Grudzielanek's single and scored when Einar Diaz hit into a double play.
Gall scored again during the three-run sixth. Pujols opened the inning with a 418-foot homer into the second deck in left-center, his 27th. Gall and Grudzielanek hit consecutive one-out singles, So Taguchi hit an RBI single and Diaz had a suicide squeeze bunt to give the Cardinals a 4-0 lead.
San Diego had three straight hits off Mulder to open the sixth and scored two runs. Greene hit an RBI single and Damian Jackson drove in a run on a groundout.
Jason Isringhausen pitched the ninth for his 28th save in 31 chances.
Mulder allowed two runs and nine hits in 5 2-3 innings, struck out three and walked one. Williams gave up four runs and nine hits in six innings.
Notes: Walker was placed on the 15-day disabled list due to a recurring neck injury. The move was retroactive to Saturday. Walker missed the final two games of a weekend series against the Chicago Cubs. ... Padres C Ramon Hernandez is scheduled to visit a Los Angeles clinic Wednesday for a second opinion on his sprained left wrist. Manager Bruce Bochy said Hernandez probably needs surgery.