LaPorta hit a go-ahead two-run homer to help Masterson (5-12) win for only the second time in 10 starts as Cleveland broke a five-game losing streak with a 3-2 win over the Oakland Athletics on Thursday night.
"It was a well-pitched ballgame and you need those to snap out of losing streaks," Indians manager Manny Acta said. "These guys are young and test your patience, but I am happy both kids contributed tonight."
While the dog days of summer have been unkind to the Indians, they got a small attendance boost on "Puppypalooza Night," a promotion in which fans bought tickets for their dogs.
The Indians avoided a three-game sweep and won for the fourth time in 17 games.
"It makes it a little more fun to come to the park tomorrow and hopefully put a [winning] streak together," Masterson said.
LaPorta hit the first pitch thrown to him from Vin Mazzaro (6-6) with two outs in the sixth inning to put Cleveland ahead 3-2. Trevor Crowe lined a two-out single to left. Then LaPorta, 0-for-5 in his career against the right-hander, broke a 4-for-44 (.091) slump with his eighth homer.
A few woofs of approval along with a genuine bark or two were heard from the crowd of 11,826. That included 269 canines, according to an Indians spokesman.
"Let's have one for the players," closer Chris Perez said. "Why not? That would be fun bringing in our dogs and walking around."
Perez, the Indians' fourth pitcher, struck out four over 1 2/3 innings for his 16th save in 20 chances. It was the first five-out, one-run save for Cleveland since David Riske did it May 13, 2003, against the Detroit Tigers.
"Was that a save or what?" Acta exclaimed. "That was a legit save, a throwback. Perez was lights-out. His command was tremendous."
Masterson was sharp, too. The right-hander threw 19-of-26 first-pitch strikes while allowing five hits and two runs over six innings for his first win in four starts since Aug. 4. He improved to 1-3 in five starts against AL West opponents, including an 11-0 defeat to Oakland on April 25 in which he gave up seven runs in four innings.
"He had real big movement on his fastball," Oakland manager Bob Geren said. "We had trouble barreling it up. We hit balls on the ground."
Gabe Gross' two-out bloop single to left put the Athletics ahead 1-0 in the second inning.
Michael Brantley tied it with an RBI single in the fifth, when the Athletics also played fine defense.
Luis Valbuena followed with a sinking liner that center fielder Coco Crisp caught at his shoetops. With Brantley on second after a single by Asdrubal Cabrera, left fielder Jack Cust, normally a designated hitter, made a diving grab of Shin-Soo Choo's bid for a bloop RBI single.
Kevin Kouzmanoff put Oakland ahead 2-1 with a two-out RBI double in the sixth. He has 15 RBIs in 11 career games against his former team, batting .368, 14-for-38.
Mazzaro gave up three runs and seven hits over 6 1/3 innings to fall to 0-4 in six starts since July 29.
"He threw the ball OK," Geren said. "Obviously, the pitch to LaPorta wasn't where he wanted it. It was still a quality start. We just didn't get enough runs today."
Mazzaro's outing gave Oakland 18 consecutive games with starters going at least six innings and allowing three earned runs or fewer, the longest streak by the franchise since the 1927 Philadelphia Athletics had 18 in a row.
Fans had to buy a ticket for their dog, have the pet on a leash and present papers that it had its shots. Dogs and owners had a parade around the warning track before the game. ... Oakland has not swept a three-game set in Cleveland since September 1989 but did take four straight Aug. 19-22, 2002. ... Oakland catcher Kurt Suzuki went 0-for-4 and is hitless in his last 22 at-bats, one short of his career worst set May 7-14, 2008. ... Left-hander Rafael Perez worked a perfect seventh. Since June 1, he has lowered his ERA from 7.20 to 3.10. ... The Indians announced that right-hander Hector Rondon, their minor league pitcher of the year in 2009, had Tommy John surgery. He's been sidelined since May 12.