Torii Hunter and Mike Trout have been friends since they shared the outfield in Anaheim five years ago, but they are competitors, too. So when Hunter launched a three-run homer in the first inning Thursday, helping the Twins pile up a five-run lead, he good-naturedly let his ex-teammate know about it.

Big mistake. Never poke the MVP.

Maybe Hunter motivated Trout, or maybe some fat pitches were all it took. Whatever the cause, the Angels’ young superstar punished the Twins all night, collecting a grand slam, a solo home run, three walks and a rally-killing running catch. It added up to a 11-8 loss, the Twins’ third loss in a row, making a tight wild-card race even tighter.

“It’s tough,” Twins manager Paul Molitor said after his team gave up four home runs in its worst pitching night since July. “Three in a row, we’re kind of fortunate that nobody’s taking advantage right now.”

The Astros fell to Texas again — 8-2, for a four-game sweep — so the Twins remain 1½ games out of the final wild-card spot in the American League, with 16 games to play. The Angels pulled within 2½ games of Houston and only one game behind the Twins, by overcoming a 5-0 first-inning deficit only a half-inning later.

“We have to bounce back from that. It’s tough to swallow — jump out early, get five runs, and all hell broke loose after that,” Hunter said after the Twins wasted his 20th home run of the season, a three-run shot that moved him into fifth place on the franchise’s career home run list, one ahead of Bob Allison. “It just was no fun out there.”

That was mostly Trout’s fault, and perhaps Hunter’s for rousing him. “We talk trash to each other during the game. The whole game,” Hunter said. “We’ve always had some competitive edge since I left. … He’s fun to watch, but it’s no fun to watch him do that against us.”

Trout was the engine to the Angels’ biggest scoring night since July. But even an MVP can’t do it alone, and Trout had plenty of help.

Chris Iannetta, a veteran catcher batting .180 on the season, singled home a run in that six-run second-inning uprising, then blasted Neal Cotts’ first pitch in the seventh inning into the left-field seats. Iannetta is 6-for-12 with three home runs in only three games against the Twins this year.

And Taylor Featherston, a rookie second baseman with a .150 average coming in, collected three hits, including a tremendous home run to left that padded the Angels’ lead.

“It got ugly. We just couldn’t contain,” Molitor said. “It’s disappointing to squander a five-run lead right out of the chute like that. Tommy [Milone, the Twins starter] didn’t have it, couldn’t command his pitches. He got four outs in about 50 pitches.”

The first game of a four-game series between the top two teams outside postseason position was supposed to be a tight, strategic affair, and a matchup of effective lefthanders. But Hunter and Trout took care of that right away, turning the game into an offensive free-for-all that kept the bullpens busy all night. Los Angeles used nine pitchers, the Twins six, in the highest-scoring Twins game of the season.

Angels starter Hector Santiago retired only two batters before being lifted amid the carnage of the Twins’ five-run first inning. Milone lasted only a few batters more, being relieved after 1⅓ innings as Los Angeles mounted a six-run rally in the second.

“It’s embarrassing, the way I pitched out there tonight,” said Milone, who faced 11 hitters and gave up four hits and three walks in his second consecutive subpar start. “To put my teammates, the bullpen in that position, I don’t know.”

Milone was pulled with the bases loaded, handing the simple task of retiring Trout with the game on the line to rookie A.J. Achter.

Trout took two Achter pitches outside the strike zone, then unloaded on a fastball clocked at 89 miles per hour. The ball landed deep in the right-center field stands, his 37th home run of the season and fourth career grand slam, and suddenly, the Twins’ early lead had vanished.

“You’re thrusting an inexperienced kid into a tough spot,” Molitor said. “Whether it’s conscious or subconscious, if you don’t throw it over, you get behind, [Trout] did what he can do. He changed the course of the game very dramatically and very quickly.”