The Chase Dollander era began with a W at Coors Field.

That’s what mattered to manager Bud Black.

“He did what he needed to do today to be the winning pitcher in a major-league game, which is what I stress to all of our starters, especially in this ballpark,” Black said. “This a tough place to pitch. But if you are determined, and if you have the will to be the starting pitcher in this ballpark, you’re going to be fine.”

And Sunday afternoon, the 23-year-old right-hander was indeed fine in his big-league debut. Not great, by any means, but good enough as the Rockies snapped their six-game losing streak with a 12-5 rout of the Athletics.

Dollander, considered one of the top prospects in franchise history, pitched five innings, giving up four runs on seven hits, including two home runs. Dollander is 1 for 1 in his big-league career, and perhaps just as importantly, he sparked positive vibes from a lively crowd of 26,207. The fans, who have had little to cheer about this season during Colorado’s 2-7 start, cheered with gusto every time Dollander fanned a batter, something he did six times.

“I think I did what I needed to do,” Dollander said. “Obviously, the ball is not going to break as much here at altitude, but I anticipated that. I thought the ball behaved liked I wanted it to. … I just need to work on being more efficient and avoiding mistakes.”

It helped that the Rockies’ hibernating offense finally awoke. Colorado snapped a franchise-worst 11-game streak scoring four or fewer runs dating back to last season. It entered Sunday having scored just 18 runs over its first eight games, but it ripped A’s pitching for a season-high 14 hits.

Center fielder Brenton Doyle led off the Rockies’ first with a home run and finished 3 for 5 with four RBIs. It was the second leadoff home run of his career. Shortstop Ezequiel Tovar hit 4 for 5 with two doubles and three RBIs. Tovar’s four hits tied a career high, and he’s batting 8 for 15 with three doubles and one triple on the current homestand after snapping an 0-for-12 slump on Friday.

“Doyle and ‘Tovie’ carried the squad today,” veteran third baseman Ryan McMahon said. “Doyle came out firing with that leadoff home run and then ‘Tovie’ hit a double. That really set the tone for us.”

Kris Bryant broke out of his early-season slump with a 2-for-5 day, including a double and an RBI.

The Rockies were leading 7-4 when Dollander departed the game. Dollander, whose fastball averaged 97.8 mph and peaked at 99.3, also fed the A’s an assortment of breaking balls. He walked only one.

“I thought he was really composed today, even when he gave up the homers,” said catcher Hunter Goodman. “His fastball is as electric as anybody I’ve ever caught.”

But make no mistake, Dollander was hurt by the long ball. Tyler Soderstrom, the A’s cleanup hitter, hit a two-run, 386-foot homer to right field in the first inning. Lawrence Butler led off the fifth with a 435-foot blast to center.

“He lost his (pitch) location to big league hitters,” Black said. “These are learning moments. But I thought his stuff was fine. He had good shape to his breaking pitches. He came out of his delivery a couple of times, maybe trying just a little too much.

“But on balance, I thought it was a good showing. Would he like to do better than five innings and four runs? Probably. And he will because he’s talented.”

Dollander, the ninth overall selection in the 2023 draft out of the University of Tennessee, said Saturday that he was prepared for the challenge of pitching at Coors, the most hitter-friendly ballpark in the majors.

“I think, mentally, I’m 100% ready,” he said. “I’ve been preparing for this moment, and I’m ready to go out there and just have fun.

“There are things that will come up, homers that probably won’t go out anywhere else. But you have to realize that things are going to happen, realize what’s happening, and be able to calm yourself down. That’s one thing I’m really good at.”

Sunday morning, a couple hours before his first major league pitch, he strolled in the outfield.

“I do that everywhere,” he said. “I got out to center field, say a little prayer and just get ready for the game.”