Right-hander Zac Gallen remained undefeated and Pavin Smith hit a three-run homer to help the Arizona Diamondbacks earn a 6-2 win over the Atlanta Braves on Monday in the opener of a three-game series in Phoenix.

Gallen (4-0) bounced back from his worst outing of the season -- six runs allowed against the Kansas City Royals on May 24 -- to pitch 5 2/3 innings and gave up two runs on seven hits. He walked two and struck out six. Gallen has allowed two or fewer runs in eight of nine starts this year.

The Diamondbacks' bullpen covered the rest of the game with 3 1/3 scoreless innings. Noe Ramirez (1 1/3 innings), Ian Kennedy (one inning) and Mark Melancon (one inning) finished the game.

Smith's home run in the first inning erased a 1-0 deficit and put the Diamondbacks ahead to stay. Smith has hit four of his seven homers on the season in the past eight games.

Atlanta's Spencer Strider (1-2) made his first major league start and took the loss. He pitched 4 1/3 innings and allowed five runs on four hits and two walks with seven strikeouts.

Arizona snapped a four-game losing streak. Atlanta has alternated wins and losses over the past six games.

The Braves scored a run in the first inning when Ronald Acuna Jr. singled, went to third on Dansby Swanson's hit and came home on a wild pitch.

After Smith put Arizona on top, the Braves got a run back in the fourth inning on Austin Riley's solo homer, his 12th. Riley has homered in back-to-back games.

The Diamondbacks rallied for three runs to go ahead 6-2 in the fifth. With one out and runners on first and second base, reliever Dylan Lee got Josh Rojas to hit a likely double-play ball to second base, but Atlanta first baseman Matt Olson failed to catch the return throw, keeping the inning alive.

The Diamondbacks took advantage of the second chance when Ketel Marte doubled to deep center field to bring home two runs. David Peralta then drove in a run with a single. All the runs were charged to Strider.

Arizona manager Torey Lovullo was ejected in the top of the fifth inning for arguing balls and strikes.

--Field Level Media