Updated

SAN FRANCISCO (AP) — Jhoulys Chacin allowed one hit in seven scoreless innings for his first major league win, Melvin Mora hit a two-run single and the Colorado Rockies avoided a three-game sweep by beating the San Francisco Giants 4-1 on Sunday.

Chacin (1-0) struck out seven and didn't allow a hit until Matt Downs' two-out double in the fifth, one of only a couple of well-struck balls he gave up as he kept attacking hitters deep into the game.

Paul Phillips drew a bases-loaded walk from Jonathan Sanchez (2-2) in the fourth to put Colorado ahead 1-0 and Ryan Spilborghs also singled home a run in the four-run fifth. The Rockies snapped their season-worst three-game losing streak.

San Francisco's Aubrey Huff homered for the second straight day, leading off the ninth with a drive against Manny Corpas.

The Rockies earned a rare victory in the Giants' waterfront ballpark, where Colorado won for only the third time in the last 12 games.

The 22-year-old Chacin walked three in his second career start and 11th big league appearance, shutting down a San Francisco lineup that scored 11 runs in the first two games. The right-hander, in the rotation because of all the injuries to the Rockies' pitching staff, made his major league debut against the Giants in the ninth inning last July 25 at Coors Field.

For the second straight series, the Giants lost the finale with a chance to sweep. San Francisco still finished an impressive 6-3 homestand against three 2009 playoff teams: St. Louis, Philadelphia and Colorado.

San Francisco leadoff man and center fielder Aaron Rowand went 1 for 4 with two strikeouts in his return from the disabled list. He missed time with small fractures of his left cheekbone and a mild concussion after he was hit by a pitch from Vicente Padilla on April 16.

Jason Giambi, in the lineup as Todd Helton got the day off, had his 19th career stolen base and first since June 22, 2008, against Cincinnati while with the Yankees.

The Rockies still must go to San Diego and Los Angeles on this nine-game road trip during a stretch of 12 straight games against NL West teams.

NOTES: San Francisco No. 5 starter Todd Wellemeyer, whose next turn is being skipped, pitched in relief. ... Colorado's Dexter Fowler, who had stolen a base in three straight games, was caught for the second time in 2010. ... Rockies LHP Jeff Francis threw four innings in an extended spring training game Saturday as he recovers from a strained pitching shoulder. He is scheduled to start for Double-A Tulsa on Thursday against Arkansas. ... Colorado closer Huston Street will throw batting practice Tuesday in San Diego, the first time he will face hitters since right shoulder inflammation sidelined him at the end of spring training. ... Clint Barmes batted second for the first time this season for the Rockies. ... Colorado first-base coach Glenallen Hill waved his hat and cheered from the top of the dugout steps when the team from his native Santa Cruz was announced on Little League day.