DENVER -- Michael Cuddyer extended his franchise-record hitting streak to 26 games with an RBI single in the first inning and rookie Nolan Arenado singled home a run with two outs in the ninth to give the Colorado Rockies a 2-1 victory over the San Francisco Giants on Saturday.
Todd Helton started the ninth for the Rockies with a two-out walk against Jeremy Affeldt. Josh Rutledge pinch ran for Helton and stole second. Arenado followed with the hit up the middle that sent the Giants to their sixth straight loss.
"I just tried to look for something up," Arenado said. "He works well when he works down, and he's got a big, old curveball. I was just looking for something up and he hung a splitty and I was fortunate enough to put a good swing on it."
San Francisco's skid is the longest since the Giants lost seven straight from June 26 July 2, 2010. The Giants have scored 18 runs in their past nine games and have dropped eight of their past nine and 11 of their past 14.
Rockies starter Jorge De La Rosa, who was forced to leave after six innings because of a bruise on his left thumb, and four relievers held the Giants to seven hits, three by Andres Torres and two by Buster Posey, whose double was San Francisco's only extra-base hit.
"I've got some guys that are struggling. That's the bottom line," Giants manager Bruce Bochy said. "A couple guys swung it well, but four or five guys struggled a lot today. It's hard to get runs on the board and keep the line moving."
The Giants wasted a terrific start by Matt Cain, who retired the final 20 batters he faced and held the Rockies to three hits and the first-inning run in eight innings. His streak began after the Giants made two throwing errors on a ball De La Rosa bunted in the second, putting runners on second and third with one out. Cain got Corey Dickerson to hit into a fielder's choice where a runner was thrown out at the plate and got D.J. LeMahieu to fly out.
"He saved us in the second," Bochy said of Cain. "We were throwing the ball all over the place. He picked the club at that point and kept them from scoring. We felt he'd done his job, gone far enough to go with Jeremy there. The two-out walk killed us."
Arenado's single was the second walk-off hit of his brief career and the Rockies' seventh walk-off hit of the season, surpassing their 2012 total.
"Nolan's one of those guys who likes to be in the box with the game on the line," Rockies manager Walt Weiss said, "and likes the ball hit to him (in those situations). You don't see that very often with young players. He's got a lot of energy, but in those situations, he's able to slow the game down."
De La Rosa was forced to leave before throwing a pitch in the seventh. He said a bruise in the webbing of his left thumb that first surfaced in the fourth inning of a June 17 start at Toronto began bothering him while warming up before this start. Nonetheless, he held the Giants scoreless for five innings before they broke through with two out in the sixth on an infield hit by Marco Scutaro and Posey's double.
Asked how he dealt with the bruise, De La Rosa said he "tried to keep the ball down and throw first-pitch strikes."
Cuddyer rolled a single up the middle on an 0-2 curveball in the bottom of the first to score Corey Dickerson, who led off with a double and was sacrificed to third.
"I started making better pitches and started getting ahead of guys," Cain said. "I wasn't getting ahead of guys as well early. I had a chance to get out of that in the first inning, and I didn't. I didn't make a good pitch to Cuddyer and obviously being as hot as he is, you make a mistake to him, he's going to get a hit."
Cuddyer's hitting streak is the longest in the majors since Jose Reyes of the Miami Marlins had a 26-game hitting streak last season from July 13 to Aug. 8.
Rafael Betancourt, who came off the disabled list on Friday and made his first appearance since May 31, retired the side in order in the ninth and was the winning pitcher.
NOTES: Giants RHP Santiago Casilla will start Sunday for high-Class A San Jose and throw one inning or 20 pitches on a rehab assignment. The reliever has been on the 15-day disabled list since May 21 after undergoing surgery to remove a bone cyst from his right knee and could be activated next weekend. ... Giants RHP Chad Gaudin (right elbow contusion) was scheduled to throw a bullpen session Saturday. He is eligible to come off the disabled list on July 6 and is expected to do so, barring a setback. ... Posey made his seventh start at first base. He has started 63 games at catcher and two as the designated hitter. With his single in the fourth, Posey has reached base in the past 47 games he has started against the Rockies. ... Rockies CF Dexter Fowler was not in the lineup for the fourth straight game because of right wrist soreness. With an off day Monday, the Rockies want to make a decision by Tuesday whether to put Fowler on the 15-day disabled list retroactive to June 25. ... Rockies RHP Edgmer Escalona (right elbow inflammation) threw 25 pitches, 20 for strikes, in 1 1/3 scoreless innings on Friday night for Triple-A Colorado Springs on what could be just a one-game rehab assignment before he is activated. He has been on the 15-day disabled list retroactive to June 10. ... SS Troy Tulowitzki (right rib fracture) took 10 light swings off a tee Friday and roughly double that number with some soft-toss swings Saturday and felt some pressure in the ribs. He fielded grounders that were rolled to him on Friday and hit to him on Saturday and threw hard, albeit with some soreness. After his next MRI, a determination will be made when Tulowitzki, who fractured the rib on June 13 and is expected to miss four to six weeks, can do more swinging.