Zack Greinke polishes his Cy Young form in Dodgers’ 4-3 win

In his previous two seasons pitching alongside Clayton Kershaw, Zack Greinke marveled at how frequently his more-celebrated teammate held the opposition scoreless.

“I just thought it was amazing he was able to do that,” Greinke said. “I don’t know why, but every game I’d find a way to give up at least a run. I don’t even know if that’s true, but that’s what it felt like.”

Greinke is now doing the same.

He pitched eight scoreless innings Sunday in the Dodgers’ 4-3 victory over the Arizona Diamondbacks, the 11th time this season in which he departed from the game without allowing a single run.

“Maybe pitching a little better this year and a little luckier,” Greinke said.

Whatever the reasons, Greinke (17-3) has an earned-run average of 1.61, which is the lowest in the major leagues.

Greinke’s latest triumph allowed the Dodgers to remain 7 1/2 games ahead of the second-place San Francisco Giants in the National League West. With 20 games remaining on their schedule, the magic number for the Dodgers to secure their third consecutive division title is down to 13.

The Dodgers are also a half game ahead of the New York Mets, their likely opponent in the first round of the postseason. By finishing the regular season with a better record than the Mets, the Dodgers would have home-field advantage against them in a hypothetical best-of-five NL division series.

Mindful of the road ahead, Manager Don Mattingly said he didn’t consider sending Greinke back to the mound for the ninth inning, even though the All-Star’s pitch count was still at 93. The decision might have cost the Dodgers three runs, but not the victory.

“I wanted to keep that inning off of him,” Mattingly said. “Just trying to keep him as strong as we can. With him and Clayton both, they pitch deep into every game, so the innings just pile up.”

Greinke has pitched 200 2/3 innings. Kershaw has pitched 201.

Greinke didn’t sound bothered by his removal.

“Didn’t really matter to me,” he said.

What he did care about was how he recovered from what he viewed as a substandard performance against the Angels six days earlier.

“Just trying to get back to pitching like normal,” Greinke said.

In his bullpen session between the starts, Greinke said he focused on repeating his delivery, something he thought he failed to do in Anaheim, where he was charged with three runs and seven hits in six innings.

Greinke said he wanted to make sure he didn’t again have the kind of “mini rough patch” he had over a three-start stretch that began in late July.

“Just tried to get out in front of it,” he said.

And he did.

Greinke allowed only three hits and two walks. He struck out eight.

With his changeup particularly effective, Greinke forced 14 ground-ball outs.

He faced the minimum number of batters through the first four innings of the game.

Greinke was even able to control All-Star first baseman Paul Goldschmidt, who entered the game a career .338 hitter against the Dodgers. Greinke struck him out three times.

“First pitch, he had some chances to hit some balls,” Greinke said. “But after I got the first-pitch strike, I was making really good pitches to him. That was the key.”

While the performance probably solidified Greinke’s position as the front-runner for the NL Cy Young Award, the pitcher himself said wasn’t particularly interested in how his candidacy compared to Kershaw’s.

“I’ve seen a bunch of articles being written about it, but I never click on it because it seems like it’s a little too early,” he said.

Up next: Left-hander Clayton Kershaw (13-6, 2.15 ERA) will face right-hander Jon Gray (0-0, 5.17) and the Colorado Rockies on Monday at 7 p.m. at Dodger Stadium. TV: SportsNet LA; Radio: 570, 1020.

dylan.hernandez@latimes.com

Twitter: @dylanohernandez