PHOENIX -- Chad Tracy received his first curtain call in what likely will be his last home series of a six-year Arizona career.
The seldom-used Tracy snapped an 0-for-18 slump with a pinch-hit grand slam in the seventh inning, sending Daniel Schlereth to his first major league win in the Diamondbacks' 8-5 victory over the San Diego Padres on Saturday night.
Tracy hit an 0-2 fastball from Luke Gregerson an estimated 432 feet into the swimming pool area in right-center for his third career slam, concluding the scoring. The Chase Field crowd cheered until Tracy came to the top step of the dugout and lifted his helmet high.
"It's awesome, to go out with a curtain in probably my last home series," Tracy said. "I appreciate the fans. It was a big at-bat, and those are the at-bats I love."
Tracy has appeared in only seven games since Sept. 9, all as a pinch hitter.
While manager A.J. Hinch said Tracy will start Arizona's final home game Sunday, it almost certainly will be his last home game for the Diamondbacks. Tracy has a $7 million option for 2010 that Arizona is expected to decline as it leans toward youth.
Tracy's seventh homer of the season was his second pinch-hit shot in two at-bats against Gregerson (2-4). He hit a two-run homer July 6 in Arizona.
"It was a good matchup that we kind of circled on the book as something we wanted," Hinch said. "Trace is a real pro. He's seen his job come and go, and trying to find that niche of how to help a young team. For him to be prepared and be ready -- things haven't gone well for him in recent at-bats. I thought the curtain call was a class act."
Mark Reynolds hit his 44th homer for Arizona, which had lost five of six and 15 of 20.
Juan Gutierrez hit two batters with pitches with two outs in the ninth but retired Oscar Salazar for his seventh save. Gutierrez is 6 for 6 since taking over for injured closer Chad Qualls on Aug. 31.
San Diego had won three straight. The Padres are 15-8 in September and 34-22 since July 28, the second-best record in the National League.
San Diego scored five runs in the fifth off Dan Haren to take a 5-3 lead, but Reynolds' homer in the sixth cut it to 5-4.
Justin Upton, who had two hits and a stolen base, opened the decisive rally with a one-out single before Reynolds singled to right. The runners moved up on a groundout before Gregerson hit pinch-hitter Miguel Montero in the back foot on a 1-2 pitch to load the bases.
Tracy had not had a hit since a single in the ninth inning Aug. 23 at Houston.
"It was a mistake. I tried to throw a fastball away out of the zone, and it came back over the middle," Gregerson said. "I thought I could get him to chase something away, but I didn't get it there. That was his pitch. He likes the ball low over the plate, and that's where I put it."
With his team trailing 5-4, Schlereth (1-4) got out of a jam in a scoreless seventh. The rookie left-hander was Arizona's first-round pick in the 2008 draft.
San Diego scored five in the fifth after a misplayed fly ball triggered the rally off Haren.
The play seemed to unnerve Haren. After pitching four shutout innings, he gave up four hits to the next five batters as San Diego took a 5-3 lead.
"In the fifth, I think he elevated the ball a little more than we saw the first four innings, and we took advantage of it," Padres manager Bud Black said. "You don't do that against Dan Haren unless he makes some mistakes up in the strike zone."
Haren gave up nine hits and struck out eight, extending his career high to 216 this season.
San Diego starter Wade LeBlanc gave up four runs in five innings. He is 2-0 with a 2.48 ERA in five September starts covering 29 innings.
Arizona scored three in the first off LeBlanc, when four of the first five batters got hits.
Arizona drew 39,352, the third-largest crowd at Chase Field all season, on a night when Reynolds bobblehead dolls were distributed. ... San Diego LHP Cesar Ramos will make his first major league start Tuesday, Black said. ... Padres 3B Kevin Kouzmanoff (back), who has missed 16 straight games, took batting practice and grounders before the game and should be ready to play by the start of the team's final homestand Tuesday, Black said.