SAN FRANCISCO -- David Peralta hit a tiebreaking single in the 10th inning, and the San Diego Padres overcame Heliot Ramos becoming the first right-handed batter to homer into McCovey Cove with a 4-3 win over the San Francisco Giants on Sunday that completed a three-game sweep.

Ramos hit a 394-foot, opposite-field drive into the water behind the right-field stands in the ninth off Robert Suarez (9-3), tying the score 2-2. There have been 167 splash homers by left-handed batters since the ballpark opened in 2000, including 104 by Giants hitters.

"It looks impossible just by looking at the wall and the weather here," Ramos said, adding that the feat was "insane" to him.

The 25-year-old said he was always aware that no right-handed hitter had a splash hit and wanted to be the first.

"We lost, obviously, but it's a special day because I did that," Ramos said. "It's a good accomplishment for me."

San Diego (85-65) is in the top NL wild-card position with two weeks to play, 1 games ahead of Arizona.

"This team is on a mission. We definitely want to get there," said Fernando Tatis Jr., who had a pinch homer in the eighth.

San Francisco has lost four straight.

With the score 2-2, Peralta drove in automatic runner Jake Cronenworth with an opposite-field single to left leading off the 10th against Camilo Doval (5-3). Peralta took third on Luis Arraez's double and scored on Donovan Solano's groundout for a 4-2 lead.

Michael Conforto hit a sacrifice fly in the bottom half against Adrián Morejon, who retired Patrick Bailey on a groundout for his second save.

The Padres improved to 9-1 in extra-inning games, the highest winning percentage in the big leagues. Manager Mike Shildt said his team has a "hunger to win and compete" and players who "do what the game calls for."

"It's about execution," Shildt said. "You get into close games, it's about execution."

Tatis said the Padres have emphasized making contact over going for the power swing, enabling them to succeed in close games.

"It's beautiful," Tatis said. "It's amazing. I haven't seen nothing like how good we have been this year on those occasions."

The Giants were scoreless in 32 innings, three shy of the San Francisco record set in 1976, before Donovan Walton's solo homer in the sixth against Martín Pérez. Manny Machado had hit a sacrifice fly in the top half.

Tatis homered against Tyler Rogers in the eighth, his fourth home run in five games.

Arraez extended his streak to 140 at-bats without a strikeout for the Padres. It's the longest since Juan Pierre went 147 at-bats without a strikeout in 2004. Arraez also had two hits to extend his hit streak to 13 games.

After calling his players' defensive effort in an 8-0 loss on Saturday "not major league quality," Giants manager Bob Melvin had his team go through defensive drills in both the infield and outfield before Sunday's game.

Melvin said with a "completely different group" compared to spring training and some players like Brett Wisely and Marco Luciano playing out of position, the Giants are working on communication and chemistry.

"It certainly isn't something that really needs to be punitive," Melvin said before the game. "But we need to try to stay on top of stuff like this, because it has to look better than it did [on Saturday]."

The Giants had one error on Sunday when Mark Canha misplayed a grounder to first by Solano in the sixth that put runners on first and second with no outs. Jurickson Profar sacrificed and Machado's fly brought in the first run.

"We make an error today that has an impact, so [it's the] little things right now and certainly a lack of offense," Melvin said.