The improbable rally off Padres closer Brad Hand (1-3) came with San Diego left-hander Eric Lauer one out away from his first major league win. Instead, San Francisco right-hander Pierce Johnson (1-1), who pitched a scoreless top of the ninth, got his first major league victory.

After the Padres rallied from a 3-0 deficit to go up 5-3, the Giants got a break when Hand hit pinch hitter Austin Slater with a pitch to start the ninth.

Buster Posey drew a two-out walk to keep the Giants alive, and Evan Longoria, who earlier committed a key two-base error, got San Francisco within 5-4 with an RBI single.

After Hand walked Brandon Belt on a full count to load the bases, Hundley came through with the game-winner, giving San Francisco its seventh win in nine games.

The Padres had jumped in front 5-3 lead, and put Lauer within reach of his first win in just his second big-league start, with a three-run fifth. The inning got rolling when Giants reliever Reyes Moronta walked the first batter he faced, Jose Pirela.

After Freddy Galvis beat out an infield single to the right side, the Padres caught a break when third baseman Longoria committed a two-base error on a ground ball by Manuel Margot, allowing Pirela to score the tying run.

A.J. Ellis followed with a sacrifice fly that scored Galvis for a 4-3 lead. Pinch hitter Chase Headley then singled to right-center, scoring Margot and completing the three-run inning.

Lauer was pulled at that point, having allowed three runs and seven hits in five innings. He walked two and struck out seven.

The 22-year-old, bombed at Colorado in his debut, barely survived the first inning. He gave up a single to Gorkys Hernandez, a triple to Andrew McCutchen and a double to Posey in his first three batters, falling immediately behind 2-0.

Two outs later, Austin Jackson singled in Posey to make it 3-0.

The first two Padres runs came against Giants starter Jeff Samardzija, who was pulled after five innings, having allowed five hits. He walked three and struck out five.

McCutchen and Longoria had two hits apiece for the Giants, who have won their past three series.

Eric Hosmer and Franchy Cordero collected a single and a double apiece for the Padres, who beat the Giants three of four earlier in April when the clubs met in San Diego.

Both teams finished with 10 hits.

--Field Level Media