Arizona outfielder Alek Thomas took the field with the Mexican flag as a cape in honor of his mother’s heritage and followed that entrance with a two-run homer against San Diego in the first game of the Mexico City Series on Saturday.

It was not enough to keep the Padres from remaining undefeated in the Mexico City Series history.

The Padres beat the Diamondbacks 6-4 Saturday in the first game of the 2026 edition after sweeping San Francisco in the first Mexico City Series in 2023.

“We can probably call this place Petco South,” Padres manager Craig Stammen said in reference to the Padres’ Petco Park home. “I think that’s a good nickname for it.”

San Diego’s Michael King (3-1, 2.28 ERA) will oppose fellow right-hander Kyle Nelson (1-2, 6.97) in the final game of the two-game set at the Estadio Alfredo Harp Helu on Sunday afternoon.

“Great moment for Alek,” said Diamondbacks manager Torey Lovullo, noting that Thomas played for Team Mexico in the World Baseball Classic this spring.

“We’re going to come out tomorrow with everything we got to hopefully split this series,” Lovullo added Saturday. “There’s nothing we can do about today. There were some good moments and obviously moments that weren’t so good.”

The Padres overcame a 4-0 deficit behind two bases-empty homers by Ty France, and their four-run seventh inning was perhaps the D-backs’ worst half-inning of the season.

San Diego scored on two singles, three walks (one intentional), a balk, an error and two sacrifice flies. Gavin Sheets’ two-run single was the big blow. During the inning, shortstop Geraldo Perdomo left the game with a sprained left ankle after committing an error.

San Diego has won 13 of its past 15 games; the D-backs have lost four of five.

“The team never gives up, especially in a ballpark like this,” Stammen said. “Keep taking good at-bats and hopefully something gets through. We’re just piecing it together, playing good baseball and never giving up.

“So far this season we’ve been able to come back, and I think once you feel that and feel that early in the season, that becomes a little bit of your identity and who you are. So far, that’s been who we are.”

King has been strongest when the Padres have needed it the most this season. Opponents are hitting .179 against him with runners on base and .080 with runners in scoring position.

King came up as a relief pitcher with the New York Yankees and credits a mindset he developed there for his ability to rise to the occasion.

“I took a lot of pride in that, in terms of when you got yourself in some bad situations, you’ve got to get yourself out,” King told The San Diego Union-Tribune. “I kind of knew those situations and how to navigate it.”

King is coming off a 2-1 victory last Sunday against the Los Angeles Angels in Anaheim, Calif., in a game in which he gave up only one hit in five scoreless innings but threw 105 pitches. He walked four batters.

Nelson enters after his worst career outing. He allowed eight runs and eight hits and retired only one of the 10 batters he faced in the first inning of a 10-4 loss to the Toronto Blue Jays last Sunday.

“I assume it is going to be kind of like pitching in Colorado,” Nelson said of the altitude in Mexico City, elevation 7,350 feet. “I’ll probably take the same approach. Just stick to my game plan, and if I need to make adjustments, make adjustments.”

King is 2-0 with an 0.00 ERA in three career starts against Arizona. Nelson is 4-3 with a 4.83 ERA in 11 games (10 starts) against San Diego. He has surrendered 11 home runs to the Padres in 54 innings.

–Field Level Media