Red Sox starting pitcher Nathan Eovaldi, left, waits for Houston’s Yuli Gurriel to run the bases on a two-run home run in the second inning of Boston’s 13-4 loss on Tuesday at Fenway Park in Boston. Charles Krupa/Associated Press

BOSTON — Red Sox starter Nathan Eolvaldi needed just five pitches to get the Astros out in order in the first inning Tuesday night.

Houston responded by hitting five home runs off him as part of a nine-run second to tie the MLB record for most homers in an inning, ending his night on its way to routing Boston 13-4.

Yordan Alvarez, Kyle Tucker, Jeremy Pena, Michael Brantley and Yuli Gurriel all went deep for the Astros, who set a franchise mark for homers in an inning. It has happened seven other times in league history.

Tucker added his second homer of the night and seventh of the season in the fourth inning – a grand slam off Tyler Danish – as Houston won for the 13th time in 15 games.

“Just some days you’re swinging it,” Astros Manager Dusty Baker said. “It was our day today.”

Jose Urquidy (3-1) allowed 12 hits and four runs, including homers to Rafael Devers and J.D. Martinez, but lasted five innings to record the victory.

Eovaldi (1-2) became the third pitcher in major league history to surrender five homers in an inning, joining Chase Anderson (Sept. 17, 2020 vs Yankees) and Michael Blazek (July 28, 2017 vs. Nationals).

Eovaldi’s line: 1 2/3 innings, eight hits, nine runs (six earned) and five home runs over 39 pitches.

It was a particularly special night for Pena, a rookie who grew up in Rhode Island and played at UMaine. His first game as a spectator at Fenway was in the 2018 playoffs Boston beat Houston in the ALCS. Tuesday was his first game actually playing in a game at the park.

“I knew I hit it hard. I didn’t know if it was hard enough to get over the Monster,” he said.

The team didn’t hear about the record until afterward.

“We have a great ballclub and we know that. We know we can do damage,” Pena said.

Devers put Boston in front 1-0 when he jumped on Urquidy’s 95 mph fastball and drove it over the center-field wall for his seventh homer of the season.

Things quickly fell apart for Boston from there.

Alvarez led off the second with a blast to center to tie it up.

Gurriel hit a grounder to third, but Devers’ throw was mishandled by first baseman Franchy Cordero, allowing Gurriel aboard.

Tucker then connected on an Eovaldi fastball and drilled his sixth homer of the season over the right-field fence.

Pena made it back-to-back homers when he sent a line drive into the seats in left center.

Eovaldi finally retired his first batter of the inning when Jose Siri flied out to right.

Martin Maldonado was next and singled, followed by a double by Jose Altuve. Brantley then cleared the bases with his homer to right that pushed the lead to 7-1.

Alex Bregman grounded out, but Alvarez kept the inning alive with a single.

Gurriel ended Eovaldi’s night when he hit the fifth and final homer of the inning to center.

“I had the quick first inning, and tried to do the same thing in the second inning, and they didn’t miss,” Eovaldi said.

Boston cut into the lead in the third after a two-run home run by J.D. Martinez.

But after having a double-play overturned on review, followed by an error by Devers that allowed Alvarez to reach on a fielder’s choice, Houston loaded the bases.

Tucker promptly cleared them with a grand slam that made it 13-3.

NOTES: Astros pitcher Jake Odorizzi was placed on the 15-day IL with lower leg discomfort. He left Monday’s game on a stretcher after he collapsed awkwardly after throwing the final pitch of the fifth inning. RHP Seth Martinez was recalled from Triple-A (Sugar Land) to take his place on the active roster. Odorizzi had an MRI on the leg, but the team hasn’t disclosed the specific injury. …  According to MLB.com, since 1974 when inning-by-inning data started, no Red Sox pitcher had given up more than three homers in an inning.