SAN DIEGO -- Clayton Mortensen picked the perfect time to put up zeros.

Mortensen clawed his way through six innings and then handed it over to the bullpen to lead the Colorado Rockies to a 3-0 win over the San Diego Padres on Monday night.

After three straight sub-par outings, Mortensen's spot in the rotation was becoming tenuous. But now with this performance, Mortensen hopes his name stays in the mix.

"I sure hope so," Mortensen said. "It definitely wasn't pretty. But to be able to keep them at zero runs and keep that one run lead was big. It worked out really nice."

Mortensen (2-3) and five relievers shut down San Diego for its 10th shutout of the season, tops in the majors. It was also the seventh time the Padres had been shut out at home, the most since they moved into Petco Park in 2004.

The Rockies won for just the fifth time in 17 games, but continued their success at Petco Park where they have won eight of the last 10.

Mortensen allowed five hits in six innings. He struck out three and walked two before he gave way to the relief corp. Huston Street pitched a perfect ninth for his 16th save in 18 chances.

Matt Reynolds, the fourth Colorado reliever, escaped a bases-loaded jam in the eighth inning. Rafael Betancourt started the inning and gave up a single and walk with one out. After he struck out Jorge Cantu for the second out, Reynolds came in and walked pinch hitter Eric Patterson before he struck out Alberto Gonzalez.

"A great pitching performance by our entire staff," Rockies manager Jim Tracy said. "I thought Clayton Mortensen actually got better as he went along. The location of his pitches improved as he got into the game."

With Aaron Cook returning from injury to make his first start this season on Wednesday, Colorado is facing a decision about its starting rotation. In his previous three starts, Mortensen had a 5.94 ERA as he lost all three starts.

"If there is any type of adjustment that we have to make, all he did was make a strong statement for himself that he wants his name tabled when that conversation comes up," Tracy said.

San Diego stranded 11 base runners.

"We had some base runners but we just couldn't break through," Padres manager Bud Black said. "We couldn't get that big hit."

Troy Tulowitzki drove in the first run in the first inning and Seth Smith had an RBI triple. Chris Iannetta added a run-scoring single off Ernesto Frieri in the ninth.

Colorado raised its June road record to 3-2, one road win more than it had in May (2-11).

Clayton Richard (2-7) took the loss despite one of his better starts this season. The left-hander gave up one run on five hits over seven innings and struck out a season-high eight with three walks.

"Most of my pitches felt good," Richard said. "In the first inning, I felt like the stuff was good. We were just kind of cruising getting quick outs. I was able to kind of pound the strike zone."

The Rockies reached Richard for a run in the first inning after Chris Nelson's one-out triple and Tulowitzki's ground ball that caromed off Richard's foot for an infield single.

San Diego had runners on second and third with one out in the first, but Mortensen struck out Ryan Ludwick and Brad Hawpe to end the inning.

Chase Headley extended his career-high hitting streak to 16 games with a first-inning single.

Game notes
The Rockies have scored three runs or less in 12 of the last 13 games. ... Colorado reliever Rex Brothers made his major-league debut in the seventh inning. ... Colorado CF Dexter Fowler (abdomen discomfort) sat out his second straight game after playing in the first 57. ... Rockies manager Tracy moved slumping OF Carlos Gonzalez into the leadoff slot from the No. 3 hole in the batting order. Tracy said the move was to jump start the struggling Gonzalez, who struck out four times in Sunday's loss at San Francisco. For the three-game series, Gonzalez was 2 for 11 with seven strikeouts. ... Padres 1B Hawpe played RF for the first time this season. Hawpe, who played right field almost exclusively for seven seasons with Colorado and Tampa Bay, had played just nine games at 1B before this season.