LOS ANGELES -- Back on May 14, Dodger Stadium was the site of Josh Collmenter's first big league start and arguably his finest performance.Friday night Collmenter once again took the mound at Chavez Ravine. The result, though, was very different. The right-hander struggled with his command and fell behind early as the Dodgers rolled to a 9-5 win over the D-backs in front of 35,169. The D-backs failed to pick up a game on the first-place Giants, who lost to the Reds. Arizona trails San Francisco by four games in the National League West. "I couldn't find a comfortable rhythm or tempo, and that really effected things," Collmenter said. "I was kind of sporadic with my fastball and got into some counts where I had to throw fastballs, and they took advantage of it." Collmenter (6-6) allowed five runs on seven hits in just 3 2/3 innings. Quite a contrast from his first start, when he allowed just two hits in six innings as the D-backs squeaked out a 1-0 win. "He was a new pitcher and we didn't know too much about him," the Dodgers' Matt Kemp said of that initial meeting. "Tonight, we knew what he had and what his pitches look like." The D-backs took a 1-0 lead when Ryan Roberts hit a two-out homer in the second off Dodgers starter Ted Lilly. Collmenter, though, ran into trouble in the third when he allowed back-to-back hits with one out before Kemp homered to center to give the Dodgers a 3-1 lead. Arizona answered with a run in the fourth to narrow the gap, but Collmenter was unable to keep things there. He allowed a pair of runs in the bottom of the inning to push the Dodgers advantage to 5-2. Kemp once again was the catalyst with a two-out, two-run single on the seventh pitch of the at-bat, a fastball up that caught too much of the plate. "I'm just thinking in that situation the pitcher is more bound to make a mistake than me," Kemp said. "In past years, I wasn't as successful with the bases loaded, now I just concentrate better." Collmenter had trouble coming in on right-handers all night, instead pulling pitches to the other side of the plate and that hurt him in that at-bat. "He fouled off a couple of tough pitches, and we were trying to get him up and see if he would swing through it, and he did a good job staying on top of the ball," Collmenter said. "It probably should have been a little bit more up. If I make a better pitch there, who knows with the way we were clawing back into the game, that was kind of the blow that shifted the momentum on their side and kind of put the game a little more out of reach." While the Kemp hit spelled the end of Collmenter's night, the D-backs did not go away quietly. Arizona rallied for single runs in the fifth, sixth and seventh innings to close the gap to 6-5. The Dodgers, though, put the game away with a three-run seventh inning, thanks in part to an error by right fielder Justin Upton. With runners on first and second, pinch-hitter Tony Gwynn lifted a fly ball to deep right that Upton seemed to have a bead on. The ball, though, eluded his glove and bounced off the warning track and into the stands for a ground-rule double. The Dodgers scored a run on the play and went on to score two more in the inning. When it was through, Upton took out his frustration in the dugout on a water cooler and garbage can. "I don't think he took his eyes off it," D-backs manager Kirk Gibson said. "It's not an easy play. You're playing in a little bit, the ball goes way back -- you can run into the wall like that. I know he showed some emotion when he came into the dugout. It was a tough play, we didn't make it. We weren't able to make some plays tonight."