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Tyler Colvin was given an opportunity to start in center field by Colorado manager Jim Tracy and, in turn, gave Juan Nicasio a chance to earn a victory with a game-tying home run in the seventh inning against Aaron Harang.

But the Los Angeles Dodgers regained the lead in the eighth on an RBI single by pinch-hitter Tony Gwynn Jr. against Matt Belisle and beat the Rockies 2-1 on Saturday night.

Tracy's intention was to get Colvin's left-handed bat in the lineup against the 6-foot-7 Harang, who was 0-3 with an 8.64 ERA in his previous five starts against the Rockies. But the 33-year-old right-hander gave up only three other hits through eight innings, and was rewarded for his effort when Gwynn came through as a pinch-hitter for him.

"Tyler's done a wonderful job in whatever capacity we have called upon him," Tracy said. "We have got quality at-bats from him as a starter and he's done a terrific job as a left-handed pinch hitter coming off the bench. He's pushing the envelope for more time. When a player does that, you have to be mindful of it and create additional opportunities for him to play."

Nicasio and Harang dueled to a 1-1 tie through seven innings in a rematch of their April 30 encounter at Coors Field, when Nicasio threw a career-high 115 pitches over six innings and allowed two runs in a 6-2 win. The Rockies right-hander gave up five hits, struck out nine and walked none.

"Juan Nicasio was great," Tracy said. "He pounded the strike zone with his fastball. And between his slider and change-up, he had enough going on to keep them at bay the entire time he was out there."

James Loney led off the eighth with an infield single against reliever Josh Outman (0-1), advanced on a A.J. Ellis' sacrifice bunt and came home when Gwynn lined an 0-2 pitch to left field.

"I was trying to get him to climb the ladder and either chase or pop up," Belisle said. "He's been really solid as a pinch hitter lately and seeing the ball well. It was a little too cute of a pitch."

Nonetheless, it certainly was to Gwynn's liking.

"I struggled against Belisle in the past. He's a short-armer, and the ball gets on you real quick, so I just tried to keep my swing short with two strikes and stay away from anything in the dirt," Gwynn said. "I was actually able to take a pretty good swing. Looking at it on tape, it looked like he threw the ball where he wanted to — about chest-high — and I was just able to get enough barrel on it."

Kenley Jansen got three outs for his third save in four attempts. It was the hard-throwing right-hander's first save opportunity since manager Don Mattingly took Javy Guerra out of the closer's role last Monday and replaced him with his setup man.

Harang (2-2) escaped a bases-loaded jam in the third, helping send the Rockies to their seventh loss in eight games and dropping them a season-worst 8 1-2 games behind the Dodgers, whose 22-11 record is the best in the majors.

Willin Rosario led off with a double over the head of center fielder Matt Kemp and advanced on Nicasio's sacrifice, but was cut down at the plate after first baseman Loney made a diving stop on Marco Scutaro's grounder in the hole and threw a perfect strike to Ellis.

Jonathan Herrera followed with a double, but Troy Tulowitzki flied out with the bases loaded after an intentional walk to Carlos Gonzalez. Tulowitzki is 5 for 28 with runners in scoring position, after batting .309 with 144 RBIs in those situations over the previous two seasons.

"That was a genuine opportunity for us to open things up a little bit and maybe create some breathing room for ourselves," Tracy said. "But we weren't able to do it, and we end up getting beat 2-1 with only four hits."

Nicasio, aided by a double play in the first, faced the minimum number of batters through four. But Andre Ethier led off the fifth with a double and scored on a one-out broken-bat bloop single to center by Juan Uribe — one pitch after Rosario went to the mound to discuss with Nicasio what he should throw on the 0-2 count.

Rosario led off again in the fifth and was plunked on the left side by Harang, who kicked the dirt in frustration. But Rosario was thrown out by Ellis when he tried to steal on a 1-1 pitch to Nicasio.

Notes: Nicasio is 0-3 with a 4.73 ERA in nine career starts on the road. ... Harang has 15 strikeouts in 31 2-3 innings over his last five starts, after fanning a career-high 13 against San Diego on April 13 — including a Dodgers franchise-record nine straight. ... Tracy, who piloted the Dodgers for five seasons — and was saddened to see the way it decayed in the final years of Frank McCourt's ownership — is encouraged by what's happening now with the new group led by Mark Walter, Stan Kasten and Magic Johnson. "I don't know how quickly they'll turn it around, but I think it's safe to say it's a very professional group of people they've assembled. There's no getting around that fact," Tracy said. "And to have a guy like Magic Johnson, having been in this town as long as he has and what he's meant to this city, he's certainly a nice guy to have out on the forefront of their ownership group."