DENVER -- Colorado Rockies pitcher Tyler Chatwood has seized a late-season opportunity at an ideal time for himself and his team.

The Rockies turned to Chatwood somewhat by default on Sept. 5 to be the No. 5 starter, and he has been getting better and better. He made his third start of the month on Friday night and muffled the San Diego Padres in Colorado's 6-1 win.

The victory left the Rockies 2 1/2 games ahead of the Milwaukee Brewers and 3 1/2 games ahead of the St. Louis Cardinals in the race for the second National League wild-card spot.

Chatwood, who is eligible for free agency after the season, worked 5 2/3 innings and held the Padres scoreless until Wil Myers belted his career-high-tying 28th homer to end Chatwood's outing.

The homer also halted Chatwood's scoreless streak at 13 innings since he returned to the rotation this month after not starting since Aug. 2. In his three starts, Chatwood is 2-0 with a 0.66 ERA.

After throwing three scoreless innings but issuing three walks and throwing just 28 of 61 pitches for strikes against the San Francisco Giants on Aug. 5, Chatwood (8-12) made a mechanical adjustment that has given him better control of his two-seam fastball and limited his walks to two in 10 2/3 innings in his past two starts.

"My two-seam's always been my pitch, and I've always been able to get it down and away to a lefty," Chatwood said. "For the most of the year, it's been running off (the plate), it's kind of flat. And I think it's because I've been fighting myself, not being able to get over my front side, firing too far across my body.

"I'm just being more square to the plate, and it's keeping my ball in the zone more. Right now I feel I'm staying through everything, and I have good angle and good depth on the ball."

The Rockies scored four runs with two outs in the second inning. Chatwood singled home the first two and DJ LeMahieu followed with a two-run triple.

After Nolan Arenado led off the eighth with his 34th home run, increasing his major league-leading RBI total to 124, Trevor Story tripled and scored on Ian Desmond's sacrifice fly.

The Rockies are 9-4 against the Padres this season with six straight victories, tying the longest winning streak against them in franchise history. Colorado also beat San Diego six consecutive times from April 5 to April 14, 2013.

A member of the Rockies' Opening Day rotation, Chatwood walked one and struck out three. He faced just two batters with a runner in scoring position and got double play balls to end the first two innings en route to getting nine outs on ground balls in a 94-pitch outing that included 52 strikes.

"What was critical tonight even though the ball-strike ratio wasn't great, when he needed to throw a strike he did," Rockies manager Bud Black said. "When he needed to get an out or a key double play like those first two innings, he got them."

Mike Dunn relieved Chatwood and got Yangervis Solarte to hit a ground ball that scooted through the legs of Arenado at third. After issuing a walk, Dunn gave way to Scott Oberg, who got Erick Aybar to ground into a force play.

In Padres starter Clayton Richard's last outing at Coors Field on July 19, the Rockies strafed him for 14 hits and 11 runs (10 earned) in 3 2/3 innings. It was much different Friday for Richard (7-14), who got 13 outs on ground balls, walked three, struck out seven and gave up seven hits and four runs, all in the fateful second inning.

The Rockies struck for four two-out runs in the second. Richard intentionally walked No. 8 hitter Jonathan Lucroy to load the bases, but that strategy backfired when Chatwood lined a two-run single to right. He did not have an RBI in his first 36 at-bats this season.

LeMahieu, batting first for the third time this season, followed with a two-run triple to left-center that dropped near center fielder Manuel Margot and left fielder Cory Spangenberg to make it 4-0. The rally began with an infield single by Carlos Gonzalez on a ball that glanced off Richard's glove to second baseman Carlos Asuaje. Mark Reynolds followed with a double.

"It's a frustrating outing because he's literally one cheap groundball away from six scoreless innings," Padres manager Andy Green said. "Him unable to control that (ball) from spinning away from him. He's still out there on the mound with the bases loaded, two outs, and the pitcher up. He got behind the pitcher, and then kind of yanked a fastball middle where it got hit.

"I think the LeMahieu ball needs to be caught. So when you look back at his outing, it's probably a six-inning two-run outing. It should be, but it ends up a four-run outing."

NOTES: Rockies CF Charlie Blackmon was not in the lineup for just the fourth time this season and did not play. He is hitless in his past 14 at-bats and 1 for his past 21. ... Padres INF/OF Jose Pirela, who suffered a left pinkie sprain Sunday while sliding, hit in the indoor batting cage but was not in the lineup. ... Rockies RHP Scott Oberg, who retired the four batters he faced on ground balls, has made eight straight scoreless appearances totaling 9 2/3 innings with no walks and 11 strikeouts in that span.