07/13/2014 11:35 EDT | Updated 09/12/2014 05:59 EDT

Bumgarner/Posey battery puts charge in Giants' win

Steve Rogers and Gary Carter. Tom Seaver and Johnny Bench. Jim Palmer and Rick Dempsey. And Chris Carpenter and Yadier Molina.

Baseball has churned out some impressive pitcher/catcher tandems over the years.

But neither they, nor any battery (pitcher/catcher combo) in major league history achieved what San Francisco Giants left-hander Madison Bumgarner and catcher Buster Posey managed Sunday afternoon against the visiting Arizona Diamondbacks: hitting grand slams in the same game.

“This game is full of strange statistics. It seems like there is a first every day,” Bumgarner, a left-handed hurler, told reporters after San Francisco’s 8-4 victory.

Posey connected for his 10th home run of the season and 71st of his career in the fifth inning off Diamondbacks starter Vidal Nuno, who had not allowed a run in his first 11 innings with the team since arriving in a trade from the New York Yankees.

Bumgarner was on base at the time, having doubled off Nuno.

In the sixth, he took Arizona relief pitcher Eric Stites over the fence for his third homer of the season and fifth in 137 major league games (264 at-bats).

“All we could do was shake our heads,” said Posey, who went deep for the first time since June 10.

The right-handed hitting Bumgarner also hit a grand slam off Colorado lefty Jorge De La Rosa in a 6-5 victory over the Rockies on April 11 (see below) to join Shawn Estes as the only Giant pitchers to hit a grand slam since the team moved from New York to San Francisco in 1958.

Atlanta’s Tony Cloninger was the last pitcher to launch two grand slams in a season, achieving the feat in the same game on July 3, 1966 versus the Giants at Candlestick Park in San Francisco.

With two hits Sunday, Bumgarner raised his season average to .275 and his on-base percentage to .302. His previous bests in both statistical categories came in 2010 with a .179 average and .220 OBP, respectively.

Bumgarner has three homers and 12 RBIs this season and five home runs and 28 RBIs in his career.

From a pitching perspective, Bumgarner might be welcoming this week’s all-star break since he’s allowed 19 earned runs over his past four starts.

While he gave up four runs and 10 hits in 6 1/3 innings, Bumgarner managed to post his 10th win of the season to end a personal three-game losing skid.