The Giants nevertheless remained 4 1/2 games ahead of second-place Los Angeles, which visits AT&T Park for a three-game showdown series beginning Friday.
At least Sandoval provided some entertainment in an otherwise dreary evening for the Giants during a benches-clearing incident in the eighth inning. Sandoval, covering his position at third base, took a throw from first baseman Brandon Belt to force out John McDonald, who approached the bag standing up instead of sliding. Sandoval's tag sent McDonald tumbling past third, prompting the pair to conduct a brief but intense nose-to-nose discussion as both teams spilled onto the field.
"I think Pablo felt like he elbowed him there in the chest," Giants manager Bruce Bochy said. "It happens. Tempers flared. It was no big deal."
Said Arizona manager Kirk Gibson, "I think Johnny Mac was going to slide and I didn't see it, but it looked like Pablo kind of stepped in front of the bag and Mac kind of tripped a little bit and Pablo pushed him. Heat of the moment. Good stuff. Good baseball stuff."
Sandoval tried to downplay the confrontation.
"It's part of the game. It happens," he said. "Those moments, you don't think about it."
McDonald denied any malicious intent.
"I was trying to slide into third and he caught the ball in front of the bag and kind of took the slide away," he said. "So I tried to go around him and I didn't make it. I tripped trying to go from sliding feet first to diving to go around him. I tripped and went right into him."
Asked what McDonald did to upset him, Sandoval said, "He tried to get to third base safe. Like I said, it's part of the game."
Sandoval later insisted, "I'm not that kind of guy. I don't like fights."
Nady's health was a much more pressing matter, since it could force the Giants to resume scrambling to fill left field, which has served as a testing ground since Melky Cabrera's Aug. 15 suspension for testing positive for testosterone.
"This is a blow for us because he's been swinging the bat well [4-for-12]," Bochy said. "He was going to get a lot of playing time, provide another power bat."
"Obviously, it's frustrating," said Nady, who endured a similar injury in 2007. "I've been here only a couple of days and get a chance to play and be part of something but I feel like I let a lot of people down."
Bochy wasn't certain how the Giants will respond to Nady's absence if he's sidelined for a prolonged stretch.
"We may have to get creative out there," Bochy said, mentioning Belt and Ryan Theriot as possibilities. Infielder Joaquin Arias also had been mentioned recently as a option.
While tests will reveal the extent of Nady's injury, diagnosing the problems of the Giants' pitchers is another matter.
"As a group, we're not quite throwing as well," Bochy admitted.
That includes Bumgarner, who has a 6.48 ERA with 20 hits allowed in 16 2/3 innings during his losing streak.
"I didn't feel that good tonight," said Bumgarner, who surrendered two-out RBI singles in the first and fourth innings. "I just tried to pitch with what I had, get through some innings, keep us in the game. You have games like that throughout the year, where you don't feel like you have any life on your ball."
By contrast, Arizona starter Trevor Cahill (10-11) almost completely subdued the Giants, retiring the first 16 batters he faced until shortstop Brandon Crawford drew a four-pitch walk. Cahill kept his no-hitter intact until the seventh, when Marco Scutaro lined a leadoff single to right field. After Scutaro shattered the no-hitter, the Giants loaded the bases with one out, ending Cahill's evening. Belt lashed a two-run single off lefty reliever Mike Zagurski.