After watching one hanging slider go by, Stephen Piscotty was not about to make the same mistake twice.

Down to their final two outs on Friday night in a game that saw the A’s trailing the Giants by six after four innings, Piscotty quickly shifted the momentum with one swing as he sent an 0-1 slider from Trevor Gott into Oracle Park’s left-field bleachers for a game-tying grand slam that capped a five-run ninth inning. The A’s completed the late comeback in the 10th as Mark Canha’s go-ahead sacrifice fly secured an 8-7 win in the Bay Bridge Series opener.

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“It didn’t look good. But you get a couple guys on board, you never know,” A’s manager Bob Melvin said. “The at-bats got pretty good late, as they typically do for us, and then Stephen hits a salami. To do that on the road and put the momentum squarely back in our dugout was huge. That was quite an inning.”

Piscotty's grand slam came on the second consecutive slider thrown by Gott, and it was his second slam of the season. His first was a walk-off against the Rangers on Aug. 4.

“I kind of had a weird take on the first pitch. [Gott] had me fooled, and I think he might have seen that,” Piscotty said. “There’s always a chance a pitcher will throw that again when they see a hitter take a pitch like that. He’s a two-pitch guy, so I had a feeling it was going to be one or the other. I was able to get one elevated.”

Piscotty etched himself into history as the 14th player in MLB history with multiple grand slams in the ninth inning in the same season. And he and Rondell White are the only players in the Expansion Era (since 1961) with a walk-off grand slam and a game-tying grand slam in the ninth inning or later in the same year. No player has ever hit three slams in the ninth or later in a season.

“It’s pretty cool,” Piscotty said of the stat. “It’s a weird game. It’s a crazy game. You find yourself in those situations sometimes. Those stats are pretty cool to relish on a little bit.”

While no other team in baseball has hit a grand slam in the ninth inning or later this year, the A’s have three through their first 20 games. Matt Olson, who hit a solo shot off Gott in the ninth on Friday, hit a walk-off grand slam in the 10th inning on Opening Day.

The A’s are the 18th team in Major League history with three grand slams in the ninth or later in a season. No club has had four.

“It’s just grinding and never saying die,” Melvin said. “We’ve seen it so many times, us come back and win at home. To do it on the road when it didn’t feel too good going into that inning and they had their closer in the game with a five-run lead, it’s just mental fortitude and continuing to grind the at-bats until something goes right.”

The thrilling comeback masked what was a rough start by rookie lefty Jesús Luzardo, who found himself in uncharted territory after enjoying a strong start to his Major League career.

Luzardo was hit hard by the Giants, which is uncharacteristic for the A’s No. 1 prospect. He surrendered two home runs and six battled balls that registered over 100 mph off the bat, per Statcast. The outing marked the first time the 22-year-old has allowed more than one home run in a game at any level as a professional.

Melvin was surprised at the lack of swings and misses generated by Luzardo, citing a good approach at the plate by Giants hitters. The lefty only had 15 swinging strikes on his fastball over 72 pitches.

“They had my number on all my pitches,” Luzardo said. “I felt like anything I threw over the plate, they were hitting. I was missing my location. They were hunting heaters and preying on mistakes, and I made a lot of them. They had a good approach.”

After allowing a solo shot to Evan Longoria in the first and a three-run shot by Hunter Pence in the third, Luzardo created a bases-loaded jam he couldn’t get out of in the fourth. A 99.2 mph two-run single roped by Longoria was the knockout blow as Luzardo was pulled with only one out in the fourth.

Entering the night having allowed five earned runs in 17 1/3 innings this season and never allowing more than eight hits in an outing at any level of pro ball, Luzardo was charged with six runs on nine hits and two walks over 3 1/3 innings on Friday.

“The last thing you ever think watching Luzardo pitch is that he would give up that many hits. You just don’t see him do that,” Melvin said. “He’s going to have plenty of good games. This wasn’t his best, but his teammates picked him up and he had a big smile in the clubhouse when I came in.”