PHOENIX — The Washington Nationals capped off a promising May with a bang by scoring 10 runs in the opening inning, ultimately defeating the Arizona Diamondbacks 11-7 on Saturday night.

All of the Nationals’ initial 11 batters reached base, piling up nine runs before the Diamondbacks recorded an out, marking it as the second-highest run total in a first inning since 1961 in the majors.

The Boston Red Sox scored 10 runs before the Florida Marlins got an out in a game on June 27, 2003, according to Elias Sports.

“I’ve been involved in some big innings, but this one was exceptional,” said Nathaniel Lowe, the Nationals’ first baseman. “It was great to challenge a strong major league starter and deliver a first inning like that. You don’t often witness such a feat.”

Washington finished May with a 15-12 record, which is their first winning month since August 2023.

Lowe — who won a World Series with the Texas Rangers in 2023 — said the team’s confidence is growing.

The Nationals improved to 28-30.

“We should get used to it,” Lowe said. “You play this game to win. Ideally, you show up every day with a chance to compete and win. Losing’s not why we play at all.”

Luis García Jr. had a double, fielder’s choice and three RBIs as the Nationals sent 16 batters to the plate in the first.

It took the Diamondbacks 30 minutes to get three outs.

“We put together some good at-bats, everybody did,” Nats manager Dave Martinez said. “We spread the ball around the field. We ended up scoring a bunch of runs, which we definitely needed tonight.”

Arizona starter Brandon Pfaadt was pulled after the first eight batters reached base.

He gave up eight earned runs and his ERA jumped from 3.90 to 5.05.

The reeling Diamondbacks have lost nine of their past 10 games.

Washington has won 11 of its past 15 and scored at least nine runs in each of the past four games.