Evan Longoria and Darin Ruf smacked back-to-back solo homers to spoil Madison Bumgarner's return to San Francisco and help the Giants post a 4-3 victory over the visiting Arizona Diamondbacks on Saturday night.

Joey Bart and Mauricio Dubon contributed back-to-back run-scoring triples later in the contest as San Francisco ended a two-game slide.

Daulton Varsho hit his first major league homer for the Diamondbacks, who lost for the 14th time in their past 16 games.

Bumgarner pitched in San Francisco for the first time since departing the franchise as a free agent in the offseason. The left-hander spent 10-plus seasons with the Giants and was part of three World Series title games.

Bumgarner (0-4) pitched just four innings in his first outing since Aug. 9 due to a back injury. He allowed two runs, three hits and two walks and struck out two while tossing 72 pitches.

Left-hander Tony Watson, San Francisco's eighth pitcher, picked up his first save of the season with a perfect ninth. Carson Kelly flied out to the wall in left for the final out.

Left-hander Caleb Baragar (4-1) was credited with the victory for the Giants. He recorded the final out of the third and pitched a scoreless fourth.

The San Francisco homers off Bumgarner were back-to-back shots in the second inning.

Longoria clubbed a 1-1 cutter 390 feet over the left-field fence to tie the score at 1.

Ruf followed and fell behind 0-2 but he slammed the sixth offering from Bumgarner -- the 2-2 pitch was also a cutter -- 453 feet over the fence in center to put the Giants ahead.

San Francisco had a runner on second with two outs in the sixth before Bart and Dubon hit the back-to-back triples.

Bart sent a deep drive off the left-center field fence that Arizona left-fielder David Peralta was unable to corral for his triple. Dubon followed with a blast to right that hit high up the wall and he cruised into third with his triple to make it 4-1.

Varsho scorched a 2-0 fastball from right-hander Trevor Gott on a line over the right-field wall and into McCovey Cove with two out in the seventh to bring the Diamondbacks within two.

Eduardo Escobar delivered a run-scoring single with two outs in the eighth as Arizona moved within 4-3. Giants left-hander Sam Selman struck out Josh Rojas with two on to end the threat.

Giants right-hander Trevor Cahill started and pitched 2 2/3 innings. He gave up one run, two hits, two walks and struck out two.

Arizona scored in the first when Kole Calhoun walked, advanced to second on a wild pitch and to third on a groundout before scoring on Christian Walker's sacrifice fly to right.

--Field Level Media