Mastroianni scored the go-ahead run from second base on an infield hit in a two-run 12th inning and the Twins beat Cleveland 6-5 on Tuesday night, tying the Indians for fourth place in the AL Central.
"A win's a win," said Minnesota manager Ron Gardenhire, pleased with the final result yet disappointed with some mistakes that let Cleveland get back into the game.
"We gave it away a little bit early," Gardenhire said. "They had chances, we had chances. Then our bullpen was super, we got a couple key hits late and were fortunate to get the win."
Mastroianni singled with two outs and stole second off Scott Maine (1-1), the team-record 10th pitcher used by Cleveland. Alexi Casilla then poked a ball between first and second that second baseman Jason Kipnis fielded in short right. But Casilla was safe when LaPorta, the first baseman, fielded Kipnis' throw, but was not on the bag. LaPorta had broken to become a cutoff man, then held the ball before reacting too late to throw out Mastroianni at home.
"That's a big mental mistake there," Indians manager Manny Acta said.
Mastroianni gambled that Casilla was going to make contact.
"I was running as soon as he swung because Alexi handles the bat well," he said. "I got to third and the coach said keep going. Then I just had to get to the plate before the ball did.
"I didn't think it was hit hard enough to get into right field, but I wasn't sure if (Kipnis) bobbled it or what happened."
It was Mastroianni's third aggressive move of the game. Two of them worked. He entered in the eighth as a pinch-runner at second base and was promptly eliminated on a scorching one-hopper hit to pitcher Vinnie Pestano.
"I was not happy with that at all," Mastroianni said. "Vinnie made a great play to get the ball, but it doesn't matter. I was overly aggressive there.
"Then in the 12th, I just took off for the steal. That was a gamble going, because if (Maine) steps off, I'm done."
Gardenhire didn't question any of Mastroianni's moves.
"He's aggressive; that's what he brings to the team," Gardenhire said. "Pestano made a great play, but the aggressiveness won the game in the end."
The Indians had runners on the corners with no outs and eventually loaded the bases in the 10th, but didn't score as they dropped to 11-38 since July 26.
"If you can't drive in the runner from third with no outs to walk off a team, you pretty much don't deserve to win the ballgame," Acta said.
The Twins broke a three-game losing streak and improved to 7-3 in extra innings.
Mauer went 3 for 4 with two walks four his fourth consecutive multihit game. He is hitting .325 and continues a late-season surge for a fourth AL batting title. Detroit's Miguel Cabrera started the day at .330, followed by Mike Trout of Los Angeles at .329.
Span opened the game with a double to right off left-hander David Huff and took third on Ben Revere's bunt single. Mauer singled home Span and Revere scored on a sacrifice fly by Justin Morneau -- his 20th RBI against Cleveland this season, tying Harmon Killebrew's team mark set in 1962 for the most against the Indians in a season.
Cleveland cut it to 2-1 in the bottom half on an RBI groundout by Asdrubal Cabrera.
One scored when third baseman Trevor Plouffe misplayed a line drive by Casey Kotchman for an error. Ezequiel Carerra put Cleveland ahead 4-3 with a run-scoring groundout, hustling down the first-base line to beat the relay throw and avoid a double play.
Minnesota tied it at 4 on Josh Willingham's RBI single in the seventh.
Huff gave up seven hits and three runs over 4 1/3 innings in his first start. He had pitched twice in relief since being recalled from Triple-A Columbus, beating the Twins with 3 1/3 scoreless innings on Sept. 7.
Walters allowed four runs -- two earned -- over five innings.
The teams threw 374 pitches and the game lasted exactly 4 hours. ... Cleveland had used nine pitchers in a game in 1971 against Washington and 2006 against the Twins. ... Indians LHP Rafael Perez has been shut down for the season with left shoulder inflammation. He has been out since April. ... Acta expects DH Travis Hafner (lower back) to play this week. Hafner has been out since Aug. 6. ... Twins RHP Matt Capps (shoulder) is expected to pitch in the Instructional League. ... The Twins are expected to announce Wednesday they are switching their Class A affiliate in the Midwest League to Cedar Rapids (Iowa) next season after eight years in Beloit (Wis.).