The San Francisco Giants treated their fans to some extra baseball in their home finale Sunday afternoon, then rallied from a 10th-inning deficit on David Villar's two-run, walk-off single to overtake the visiting Arizona Diamondbacks 4-3.

The win allowed the Giants (80-79) to finish with a home record of 44-37, 10 games worse than the 54-27 that helped produce a 107-win season a year ago.

After Jake McCarthy's third hit of the game, a one-out single, had scored designated runner Daulton Varsho from second base to put Arizona up 3-2 in the top of the 10th, reliever Taylor Widener (0-1) failed to retire any of the three batters he faced while attempting to record a first-ever save.

With Mike Yastrzemski starting the inning on second, Wilmer Flores walked and J.D. Davis loaded the bases with an infield single, setting the stage for Villar, who hit the first pitch he saw into left field.

Jharel Cotton (4-2), who allowed the Arizona run in the top of the 10th, was credited with the win.

The Diamondbacks trailed 2-1 entering the eighth, but got an RBI double from Josh Rojas, leading to the late dramatics.

The run came as an immediate response to Austin Slater's pinch-hit home run leading off the seventh that had given the Giants a 2-1 lead. The homer was Slater's sixth of the season.

Diamondbacks starter Zach Davies limited the Giants to one run and two hits in the first five innings. He left a 1-1 tie having walked five and struck out three.

San Francisco's run off Davies came in the first when Flores doubled, took third on a single by Joc Pederson and scored on a sacrifice fly by Evan Longoria.

Giants "opener" Scott Alexander and reliever Thomas Szapucki shut out Arizona over the first three innings on three hits before the visitors drew even in the fourth against San Francisco's third pitcher, Alex Young, on back-to-back doubles by Carson Kelly and McCarthy.

Villar finished with two hits and Flores scored twice for the Giants, who head south to wrap up the season with three games at San Diego beginning Monday night.

Rojas joined McCarthy with three hits for the Diamondbacks, who finish the year with three at Milwaukee. Christian Walker and Varsho collected two hits apiece for Arizona, which out-hit the hosts 13-6.