BALTIMORE — For the second time this season — and for the second day in a row — the Orioles got to experience the thrill of a walk-off victory at Camden Yards. This wild, back-and-forth Memorial Day matinee felt like one Baltimore needed to win, too.

To repeat: This one was wild. And once again, Colton Cowser was the hero.

Cowser lifted the O’s to a 9-7 victory with a two-run home run in the bottom of the 13th inning, as they took the series opener against the American League East-rival Rays on Monday afternoon. It marked their first win this season against Tampa Bay, which swept a three-game set between the two teams at Tropicana Field last week.

The Orioles (24-30) celebrated their first walk-off win of the year on Sunday afternoon, when Cowser’s three-run homer in the ninth capped a come-from-behind effort in the opener of a doubleheader split vs. the Tigers.

Cowser had never had a walk-off hit during his four-year MLB career prior to Sunday.

The path to the 13th inning was stunning, to say the least.

Rico Garcia continued his dominant season out of Baltimore’s bullpen by keeping Monday’s game tied at 2 in both the ninth and 10th. The Rays loaded the bases with one out in the 10th, but Garcia (who now has a 0.77 ERA in 25 appearances) struck out Richie Palacios and got Cedric Mullins to line out to first base to escape the jam unscathed.

However, the O’s couldn’t score in the bottom of the 10th, as automatic runner Jackson Holliday was still standing at second base when the inning ended.

Tampa Bay took a 4-2 lead in the 11th, as Victor Mesa Jr. opened the frame with a two-run home run off right-hander Tyler Wells. But Wells retired the next three batters to keep the game within striking distance.

Pete Alonso cut the Rays’ lead to 4-3 by opening the bottom of the 11th with an RBI single, and he ended up on second following a misthrow by left fielder Chandler Simpson — Tampa Bay’s fourth error of the day. Alonso then scored on a single by Jeremiah Jackson that knotted the game at 4. But the Orioles again could not walk it off.

In the top of the 12th, the Rays took a 5-4 lead on a sac fly by Jonathan Aranda. And in the bottom of the 12th, the O’s tied it at 5 on an RBI fielder’s choice by Gunnar Henderson, as Cowser evaded a tag by catcher Nick Fortes on a throw home. (Cowser was originally called out, but it was overturned by replay review.)

Tampa Bay took a 7-5 lead in the top of the 13th on an RBI single by Mullins and a sac fly from Fortes. But Baltimore quickly responded with an RBI double from Leody Taveras and a sac fly by Holliday that made it 7-7.

That set the stage for Cowser, who blasted a Statcast-projected 425-foot home run over the right-center-field wall to end it.