LOS ANGELES -- Clayton Kershaw was allowing too many homers earlier this season, but he demonstrated Tuesday that he is as dominant as ever.

The Los Angeles left-hander did not allow an earned run for a third consecutive start, throwing seven shutout innings, and the Dodgers won the opener of the three-game series against the Arizona Diamondbacks 4-3 at Dodger Stadium.

Kershaw (13-2) allowed two hits and two walks while striking out 11 on 117 pitches. The three-time NL Cy Young Award winner and four-time NL ERA champion lowered his ERA from 2.32 to 2.19 and became the first 13-game winner in the majors this season.

On June 19, Kershaw yielded a career-high four home runs in a 10-6 win against the New York Mets, giving him a career-high 17 allowed on the season. However, he hasn't been tagged for a homer or an earned run in 20 innings since, racking up three more wins in that span.

"You guys kept telling me I was giving up so many homers, so I was ready to stop doing it," he said.

Justin Turner and Yasmani Grandal drove in two runs apiece as the first-place Dodgers (56-29) extended their lead over the second-place Diamondbacks (52-32) to 3 1/2 games in the National League West.

Los Angeles has won 21 of its past 25 games.

Daniel Descalso hit a three-run homer off Dodgers closer Kenley Jansen with two outs in the ninth to prevent the shutout. Jansen walked the next batter before striking out pinch hitter Chris Herrmann to seal his 19th save.

"Right up until the final moment of the game, we thought we had a chance," Arizona manager Torey Lovullo said.

Kershaw didn't surrender a hit until there was one out in the seventh inning. Arizona shortstop Chris Owings was jammed and sent a slow roller to second baseman Logan Forsythe. First baseman Cody Bellinger went for the ball instead of the bag, and Kershaw was late covering.

Diamondbacks catcher Chris Iannetta, who drew Kershaw's only two walks, followed with a single to left to put runners on first and third with two outs, but Descalso grounded to second to end the only threat against Kershaw.

Turner came into the day leading five players for the NL Final Vote into the All-Star Game next week in Miami, and he knocked in the game's first two runs.

He singled off the top of the wall in the first inning to drive in Forsythe, then hit a solo homer to center field to lead off the third, his eighth of the season.

Forsythe came in 8-for-10 in his past three games, and he went 3-for-3 off Arizona starter Patrick Corbin on April 15 at Dodger Stadium. He finished 1-for-3 Tuesday, recording a leadoff double down the right field line in the first.

Los Angeles' Chris Taylor doubled with one out in the third before scoring on Grandal's two-out single to right for a 3-0 lead.

Corbin (6-8) struck out five through the first two innings, but four of the first five hits he surrendered were for extra bases. He was lifted after 4 2/3 innings of three-run ball. He allowed seven hits and two walks while striking out eight.

"I thought he had good and bad moments," Lovullo said of Corbin. "I thought he could have really fallen apart and come off the mound, given up seven or eight runs, but he only gave up three runs through four innings, and we sent him back out there and he almost wiggled through that fifth inning."

NOTES: The Dodgers placed LHP Hyun-Jin Ryu on the 10-day disabled list prior to the game with left foot soreness. It is the seventh time Ryu has been on the disabled list since he was acquired by the Dodgers in December 2012. The Dodgers recalled RHP Ross Stripling from Triple-A Oklahoma City. ... Diamondbacks CF A.J. Pollock was reinstated from the disabled list prior to the game and went 1-for-4 with a ground-rule double in the leadoff spot. Pollock missed the past seven weeks with a groin strain sustained May 14. To make room on the roster, Arizona optioned INF Ildemaro Vargas to Triple-A Reno. ... Arizona LF Yasmany Tomas was diagnosed with a mild groin strain, manager Torey Lovullo said before the game. Tomas exited a rehab game at the rookie level on Saturday. The setback is unrelated to the groin tendinitis that caused Tomas to go on the 10-day DL on June 6, Lovullo said.