(AP) -- Jose Valverde retired pinch-hitter Yadier Molina with the bases loaded for the final out, and the Arizona Diamondbacks held off the St. Louis Cardinals 6-5 on Sunday for their fifth straight victory.

Tony Clark's two-run double capped a four-run rally in the seventh inning that put Arizona up 6-4. Justin Upton tied the score with his first homer since Aug. 7 and Chris Young also connected for the Diamondbacks, who moved three games ahead of second-place San Diego in the NL West.

The Cardinals fell three behind first-place Milwaukee in the NL Central.

Yusmeiro Petit (3-4) pitched two innings of one-hit ball for the win. Valverde came on in the ninth for his major league-leading 45th save in 52 chances.

After retiring his first two batters, Valverde loaded the bases when pinch-hitter Jim Edmonds doubled, Albert Pujols walked and Ryan Ludwick was hit by a pitch.

Pinch-hitter David Eckstein drew a walk that made it 6-5, but Valverde quickly got ahead of Molina and retired him on an easy fly to right.

Four Diamondbacks relievers combined for five innings of two-hit relief.

The Cardinals held a 4-2 lead and right-hander Kip Wells, making a rare relief appearance, had stymied Arizona on one hit over four innings before Chris Snyder opened the seventh with a double.

After Upton settled into the batters' box to face Wells, St. Louis manager Tony La Russa pulled the right-hander in favor of Ryan Franklin (4-3). But Upton hit Franklin's third pitch 411 feet into the left-field stands to tie the game at 4.

Pinch-hitter Jeff Salazar doubled and Eric Byrnes drew a two-out walk before Clark hit a line drive into the right-field corner for a 6-4 Diamondbacks lead.

The Cardinals did all their damage during a six-batter span in the third inning against Doug Davis, scoring four runs on five hits.

Kelly Stinnett walked and pinch-hitter Brian Barden doubled over the third-base bag. Miguel Cairo tripled off the right-field wall, scoring Stinnett and Barden to tie it at 2.

Upton was shaken up when he ran into the fence chasing Cairo's triple. He appeared to injure his left knee when it slammed into one of the supports, tearing his uniform pants, but remained in the game.

Davis struck out Skip Schumaker, but Brendan Ryan reached on an RBI infield single and Pujols added a run-scoring double for a 4-2 lead.

St. Louis' Brad Thompson allowed two runs and four hits in two innings, his shortest start of the season.

Mark Reynolds hit a one-out single off Thompson in the second and Young followed with his 29th homer into Arizona's left-field bullpen.

Notes:@ RHP Bob Wickman made his Diamondbacks debut in the fifth, walking one and striking out one in a scoreless inning. It was his first appearance since Aug. 23 with Atlanta. ... Molina was scratched from the lineup Saturday with concussionlike symptoms.

(Copyright 2007 by The Associated Press. All Rights Reserved.)