Rookie right-hander Max Scherzer earned another start after striking out a career-high 11 in his last outing.
Schrezer will face Cincinnati on Sunday, manager Bob Melvin said, a week after he struck out 11 in five innings during a no-decision at Los Angeles. Scherzer gave up two runs on James Loney's broken-bat single in the first inning but retired 12 in a row after giving up a leadoff single in the second.
Scherzer, 0-2 with a 3.00 ERA in 13 appearances with the Diamondbacks, struck out six in a row and eight of nine starting in the third inning.
"We think it is the right thing to do," manager Bob Melvin said as the D-backs attempt to catch the Dodgers in the NL West.
The D-backs clocked Scherzer's fastball at 97 mph against the Dodgers, slightly below the Dodger Stadium's reading of 98 and 99, but it was the command of his breaking ball and changeup that got Melvin's attention. Scherzer got six of his strikeouts on off-speed pitches.
"To be a starter in the major leagues, you need your secondary pitches. Both were never better," Melvin said.
Scherzer, 24, will replace Yusmeiro Petit, who has given up 10 runs -- including four home runs -- and 18 baserunners in his last 7 1/3 innings.
GIANTS 5, DIAMONDBACKS 4: Arizona lost its fifth consecutive game, tying a season high, when Giants 2B Eugenio Velez hit a one-out, walk-off single in the ninth inning. RHP Jon Rauch, who took the loss, fell to 0-5 with the D-backs since being acquired from Washington on July 22.
C Chris Snyder hit a two-run home run with no outs in the top of the ninth to tie the game at two. His subsequent poor defensive fundamentals - going two feet out in front of home plate to corral RF Jeff Salazar's throw on the Velez single rather than let it come to him at the plate - gave back the winning run. LHP Doug Davis gave up two runs in 5 1/3 innings and also had a run-scoring single.
The D-backs (71-73) fell two games under .500 for the first time all season.
--RHP Jon Rauch, acquired July 22 with an eye toward taking over the closer's role in 2009, fell to 0-5 with a 6.41 for the Diamondbacks after being charged with a 5-4 loss Tuesday. He gave up a single and a walk to the other two batters he faced in the bottom of the ninth inning at San Francisco. "I don't want to talk about it," Rauch said of the frustration level he felt. "If you think I'm going sit here and talk about how (poorly) I've been pitching, how I keep making mistakes left and right and it keeps putting this team farther and farther out of playoff contention ... I really just don't know what to do right now. I wish I had an answer."
--C Chris Snyder had three hits Tuesday, finishing a triple short of the cycle. He hit his 20th double of the season, matching a career high set last year. His homer was his 15th, extending his career high, which had been 13 in 2007. He already has set a career high with 63 RBI.
--The D-backs (71-73) lost for the fifth consecutive time Tuesday, tying their longest losing streak of the season. They are 2 1/2 games behind Los Angeles and two games under .500, the first time they have been that far out of the first place or under .500. They have lost seven games in the standings to the Dodgers in the last 11 days.
--The D-backs lead the major leagues with 83 quality starts, but they have had only four in the current 15-game stretch in which they are 3-12. The rotation's ERA is 7.28 in the past 15 games.
BY THE NUMBERS: 2 -- Players in franchise history with seasons that included double-digit doubles, triples and homers: Stephen Drew (2008) and Steve Finley (1999, 2003).
QUOTE TO NOTE: "Offensively, he's growing at the rate we felt he could. Defensively, he's as solid as anyone in the league." -- D-backs third base and infield coach Chip Hale, on SS Stephen Drew's breakout season.
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