SAN FRANCISCO -- Tim Lincecum's modest win streak is over, the Giants are struggling to hit at home and now their lead in the NL West is gone.
While it was another step forward for the Giants' two-time NL Cy Young Award winner, it was also a stark reminder of how they've struggled offensively at AT&T Park this year.
San Francisco hasn't scored in its last 14 innings at home and was shut out for the fifth time this season -- sixth overall -- at its waterfront ballpark.
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"Timmy was fine, we just didn't swing it," manager Bruce Bochy said. "It's pretty simple. [Lincecum] wasn't the problem. Three hits was the problem."
The Giants swept the Rockies in a three-game series at Coors Field a week ago when they outscored the hosts 35-13.
This time around, San Francisco only got one runner to third base.
"We go into every game with the same amount of confidence and it doesn't matter where we're playing," said shortstop Brandon Crawford, who had two of the Giants' three hits. "We just haven't seemed to get hits here lately."
San Francisco (61-52) fell into a tie with the Los Angeles Dodgers for first place in the NL West.
Tyler Chatwood combined with three relievers on the shutout, just the third by the Rockies this season.
Wilin Rosario doubled twice and scored a run while Tyler Colvin added two hits and an RBI for Colorado. The Rockies scored all their runs off Lincecum, who had allowed only two runs in his previous two starts.
"This is the kind of game you really feel like a team," said D.J. LeMahieu, who singled and scored in the third. "The pitchers are doing their job, the defense goes great and the offense scratches out some runs."
Chatwood (2-2) scattered three hits over five innings in his second start this season. The right-hander, who began the season in the bullpen, had two strikeouts and two walks.
Adam Ottavino pitched two innings, Matt Belisle worked the eighth and Rafael Betancourt pitched a 1-2-3 ninth for his 20th save.
Lincecum (6-12) repeatedly fell behind in the count and the Rockies took advantage.
LeMahieu singled leading off the third, was sacrificed to second and scored from third on Dexter Fowler's single to left-center. Fowler tried to stretch his hit into a double but was thrown out by San Francisco center fielder Angel Pagan.
In the fourth, Rosario doubled and scored on Colvin's RBI single to make it 2-0.
Lincecum, who had won his previous two starts, struck out three and walked two in seven innings.
"I gave them too many good pitches to hit," he said. "It was just a tough day. Losing, getting shut out like that at home, is tough for us."
Chatwood wasn't overpowering but he was effective.
The Giants got a runner to second in the third and fourth but failed to advance against the right-hander.
In the fifth, San Francisco put runners on the corners with one out but Chatwood worked out of it with some help from his teammates. Chatwood struck out Lincecum, and Rosario threw out Crawford trying to steal second on the same pitch.
Colorado's defense came up big again in the sixth.
With Melky Cabrera on first following a two-out error by third baseman Chris Nelson, LeMahieu knocked down Hunter Pence's sharp grounder up the middle and scrambled to make a one-handed flip to shortstop Josh Rutledge covering the bag.
Nelson made up for his gaffe and gave the Rockies some breathing room with a sacrifice fly in the seventh that knocked in Colvin to make it 3-0.
Colorado's pitching did the rest.
Ottavino pitched out of a two-on, one-out jam in the seventh, and San Francisco didn't manage a baserunner the rest of the way.
San Francisco 3B Pablo Sandoval (strained hamstring) played five innings during a rehab start in the minors and could rejoin the big league club by Monday, according to Bochy. ... Colorado 1B Todd Helton underwent surgery to repair a torn labrum in his right hip, bringing an end to a disappointing season. Helton, who turns 39 on Aug. 20, has said he plans to return for the final season of his two-year contract. ... Rockies SS Troy Tulowitzki (groin) is running without pain but isn't yet close to playing. Tulowitzki has been on the DL since May 31. ... RHP Matt Cain (10-5) tries to end his four-start winless streak for the Giants on Saturday. LHP Drew Pomeranz (1-6), whose only win this season came against San Francisco, pitches for the Rockies. ... A plaque commemorating Cain's perfect game against the Houston Astros on June 13 was placed on a walkway outside the right-field wall at AT&T Park during a pregame ceremony.