Dallas Keuchel pitched as advertised in his Twins debut Sunday, with a fastball that reached 89 miles per hour and a lot of ground balls, and he let his offense provide the fireworks.

Trailing by a run in the ninth inning, Max Kepler crushed the first pitch he saw from Diamondbacks closer Paul Sewald into the right field seats. Two batters later, Matt Wallner launched a walk-off, two-run homer in a stunning 5-3 victory at Target Field following a pregame weather delay that lasted two hours and 12 minutes.

Wallner, after the first walk-off hit of his career, was drenched by two water coolers as he crossed home plate.

The Twins were outhit, 11-6, but they watched the D-Backs hit 2-for-11 with runners in scoring position and strand 12 runners on base.

Keuchel walked a tightrope in his five-inning debut, permitting eight hits and two walks, but only one run. Third baseman Willi Castro saved two runs from scoring in the third inning when he snared a line drive that left Christian Walker’s bat at 112 miles per hour.

With a runner on first base in the fourth inning, Matt Wallner made a sliding catch while avoiding Castro in shallow left field.

The Diamondbacks had runners on the corners with one out in the fifth inning when Tommy Pham ended Keuchel’s shutout by beating out an attempted double play. The next batter, Walker, reached on an infield single and both runners advanced a base on a double steal. Keuchel stranded the runners with a comebacker to the mound, showing some emotion with a punch into his glove as he walked toward the dugout.

Keuchel didn’t record a strikeout against any of his 23 batters, but he worked ahead in counts with 18 first-pitch strikes. He’s always rated near the bottom of the league in fastball velocity, topping out at 89 mph Sunday, but his specialty is generating ground balls.

It was a long road for the 35-year-old Keuchel to work his way back onto a major league mound. He had a disastrous 2022 season and remained unsigned at the start of this season. The Twins signed him to a minor league deal in June, a low-risk move to add some starting pitching depth, and he had a 1.13 ERA in six starts.

When Keuchel arrived in the Twins clubhouse Friday afternoon, he walked past every locker and introduced himself to his new teammates with a handshake, “Hey, I’m Dallas.” When he reached Carlos Correa’s locker, his former teammate with the Astros, they broke into a hug.

The Twins didn’t have many baserunners against D-Backs ace righthander Zac Gallen, but they capitalized in the sixth inning. Willi Castro hit a one-out double to right field, their first baserunner to reach second base, and he moved to third on a wild pitch. After Edouard Julien drew a walk, Correa dropped a go-ahead, two-run single to left field.

Correa broke into a smile as he looked at his teammates in the dugout and gave a high-five to first-base coach Hank Conger. The hit must have been a sigh of relief to Correa, who grounded into double plays in each of his first two at-bats. He’s grounded into a league-leading 22 double plays this season, six shy of the franchise record (Harmon Killebrew in 1970 and Trevor Plouffe in 2015).

Correa’s two double plays spoiled the only momentum the Twins had against Gallen for most of his outing. Julien was the lone hitter who reached base against him through the first five innings, drawing a six-pitch walk in the first inning after starting in a 0-2 count, and he lined a first-pitch cutter to left field for a single in the fourth inning.