Atlanta lost 6-4 in 11 innings on Wednesday night for its third straight loss overall.
The Braves fell to 17-21, the latest in the season they’ve been four games under .500 since 1992.
On Thursday, the team will look to left-hander Horacio Ramirez to avoid the sweep. The Braves have only scored 22 runs in his seven starts this season.
Ramirez has a 2.25 ERA, and despite the lack of support, is coming off a 2-0 victory over the Brewers on Friday. He allowed five hits and three walks in eight innings.
Arizona’s Luis Gonzalez homered twice in Wednesday’s victory.
Gonzalez, who gave the Diamondbacks a four-run lead with a two-run shot in the sixth, broke a 4-4 tie with his 12th homer, a solo shot off Atlanta reliever Armando Almanza, in the 11th. Steve Finley followed with his major league-leading 13th to give Arizona a two-run cushion.
For Gonzalez, it was the 20th multi-homer game of his career, and his second since May 10. The Diamondbacks now have consecutive wins for just the second time in their last 11 games.