DENVER (AP) Nolan Arenado and Carlos Gonzalez hit back-to-back homers in the first inning, backing a strong outing by Jorge De La Rosa, and the Colorado Rockies beat San Francisco 2-1 on Friday night to send the Giants to their seventh straight loss.

De La Rosa (9-6) allowed one run and six hits in seven innings. He didn't walk a batter and struck out seven. Two of the strikeouts came in the sixth inning, helping him get out of a jam and he induced an inning-ending double play grounder from Juan Perez after giving up a one-out single to Kelby Tomlinson in the seventh.

Chris Heston (11-9) went 5 2-3 innings for the Giants and allowed seven hits and two runs, both on the solo homers in the first.

More from FoxSports

John Axford worked a scoreless ninth for his 19th save.

Gonzalez hit a towering drive in the first inning that narrowly sailed foul. He hammered the next offering from Heston over the wall in center field for his 36th home run of the season, extending a career high. Arenado followed by connecting for his 35th of the season, joining Dante Bichette (1995) and Larry Walker (1999) as the only Rockies to homer in five straight games.

It was the second time this season that Gonzalez and Arenado teamed to go deep in successive at-bats.

San Francisco pulled to 2-1 in the sixth on a one-out RBI single by Angel Pagan. Matt Duffy singled and Buster Posey was hit by a pitch around a strikeout by Brandon Belt to load the bases. But De La Rosa escaped further damage by striking out Marlon Byrd.

Rockies first baseman Justin Morneau, reinstated from the disabled list before the game, played for the first time in nearly four months after being sidelined by concussion symptoms. He singled in his first at-bat and finished 1 for 4.

TRAINER'S ROOM

Giants: SS Brandon Crawford played for the first time in four games. He missed the previous three games because of a calf injury suffered Monday when he was hit by a pitch in a game against the Los Angeles Dodgers. ... INF Joe Panik has begun a rehab assignment with Triple-A Sacramento. He has missed the last 32 games with a back injury.

Rockies: Utility player Matt McBride was designated for assignment to clear a spot on the 40-man roster for Morneau.

UP NEXT

Giants: RHP Jake Peavy (4-6) faces Colorado for the first time this season. He's 5-7 with a 3.95 ERA in 20 previous starts against the Rockies.

Rockies: RHP Chad Bettis (6-4) is 1-0 with a 4.09 ERA in two starts since returning from a six-week stint on the DL due to inflammation in his pitching elbow.