SAN FRANCISCO -- The San Francisco Giants got a three-run homer from Hunter Pence in the first inning and 3 1/3 innings of near-perfect pitching from three relievers Monday night en route to a 4-2 victory that ended the Colorado Rockies' five-game winning streak.
Santiago Casilla, Jeremy Affeldt and Sergio Romo picked up a struggling Madison Bumgarner (2-0), finishing off the left-hander's second win of the young season by retiring 10 of the final 11 Rockies. Ten of the 25 batters who faced Bumgarner reached base.
The Rockies (5-2) hadn't lost since Opening Day, when they fell 5-4 in 10 innings to the Brewers in Milwaukee. Colorado had scored at least five runs in each of its five wins since then, including a total of 20 in its just-completed home sweep of the San Diego Padres.
The Giants (4-3), playing their first home night game of the season, were coming off successive daytime home losses to the St. Louis Cardinals.
Even though Pence's two-out, three-run shot -- his third of the season -- in the first inning staked San Francisco to an early lead, Bumgarner struggled through 5 2/3 innings. He allowed five hits and five walks (one intentional) but only two runs.
The Rockies knocked the left-hander from the game after 104 pitches, the last of which Chris Nelson grounded into left field for an RBI single that had narrowed Colorado's deficit to 3-2.
With the potential tying run at second base, Casilla entered and struck out Yorvit Torrealba to retain the Giants' lead.
Casilla stayed on to pitch a 1-2-3 seventh, and Affeldt was similarly flawless in the eighth. Romo yielded a booming double to Josh Rutledge to open the ninth -- the first baserunner he'd allowed this season -- before buckling down to record his fourth save in four tries, striking out the next three Rockies he faced.
The win improved Bumgarner's career record against the Rockies to 6-3, including 4-0 the past two seasons.
Jorge De La Rosa (0-1) took the loss, allowing only three more hits and no more runs through six innings after having surrendered three of each in the fateful first.
The Giants added an insurance run in the eighth on a two-out single by Buster Posey off Chris Volstad that scored Angel Pagan. The RBI was the first of the season for the reigning National League Most Valuable Player.
NOTES: Colorado center fielder Dexter Fowler went 0-for-4, ending his hot streak. Fowler began the season with at least one hit and one run in each of Colorado's first six games, a franchise record. ... Rockies slugger Wilin Rosario, who tied a franchise record for a catcher by hitting three home runs in the season's first six games, was not in the starting lineup against Bumgarner, replaced by ex-Giant Torrealba. ... Few things are more of a sure thing in baseball than when Bumgarner gets three or more runs of offensive support. He's now 32-4 in such games. ... The Giants didn't score a first-inning run in their first six games. ... When Pagan grounded into a 1-6-3 double play in the fifth inning, it was the Giants' 10th of the young season, extending the club's league lead in that dubious category. ... The Rockies had a total of just 13 at-bats against left-handed pitchers in their first six games.