SAN FRANCISCO -- Jae-Gyun Hwang homered in his major league debut, a tiebreaking drive in the sixth inning that led the San Francisco Giants over Colorado 5-3 Wednesday and extended the Rockies' losing streak to a season-high eight games.
A 29-year-old who starred for South Korea's Lotte Giants, Hwang was brought up from Triple-A Sacramento before the game and inserted into the starting lineup at third base, batting fifth.
He grounded out in the second inning, hit a run-scoring grounder in the fourth that cut Colorado's lead to 2-1, then broke a 3-3 tie when he homered against Kyle Freeland (8-6). Hwang was given a standing ovation from fans as he rounded the bases and was mobbed by teammates when he got back to the dugout.
He took a called third strike in the eighth, completing a 1-for-4 day.
Ty Blach (5-5) gave up three runs -- one earned -- seven hits and three walks in 6 1/3 innings, George Kontos, Steven Okert and Hunter Stickland combined for one-hit relief. Strickland retired Ian Desmond, his only batter, on a flyout for his first save this season.
San Francisco's bullpen pitched 13 1/3 scoreless innings during the three-game sweep. The Giants entered the series on a five-game skid and with 12 losses in 13 games.
Freeland gave up four runs and seven hits in six innings.
Nolan Arenado's two-run single put Colorado ahead in the first, but San Francisco took a 3-2 lead in the fourth on Hwang's grounder and Nick Hundley's two-run homer.
A day after he was called up from Triple-A Albuquerque, Mike Tauchman singled in the tying run in the sixth, his first big league hit and RBI.
With the bases loaded in the eighth, Brandon Belt hit a one-out, bases-loaded grounder that shortstop Trevor Story stopped with a dive. Story threw to second for a forceout, and second baseman Pat Valaika's throw sailed over first as Gorkys Hernandez scored. The Rockies argued that Austin Slater slide interfered with Valaika's throw, but umpires upheld the clean slide after a video review, and Belt went to second on the throwing error.
Arenado made a diving play to his glove side to snag Blach's third-inning grounder, then from a near-sitting position spun and threw to first for the out.
Rockies: INF DJ LeMahieu did not play after leaving Tuesday's game in the fourth inning with a strained right groin. He had been the only player to appear in each of the Rockies' first 80 games. ... OF Carlos Gonzalez, out with a right shoulder strain, took swings in the batting cage. "From what I saw it's not 100 percent with bat speed, but it's with nice intent," manager Bud Black said. "He's making some aggressive swings. He's getting better."
Giants: The Giants placed RHP Mark Melancon on the 10-day DL for the second time this season. Melancon has a right pronator strain. ... The Giants placed INF Conor Gillaspie on the DL with back spasms. ... Dan Slania was recalled from Double-A Richmond.
Rockies: RHP Jon Gray (0-0, 4.38 ERA) is to come off the DL and start Friday's series opener at Arizona. Gray, the Rockies' opening-day starter, has been on the DL since April with a stress fracture on his left foot.