With All-Star closer Chris Perez unavailable and the Indians entering with a six-game losing streak, Pestano went from his role as setup man to get the final four outs and save a 4-3 win over the Texas Rangers on Saturday night.
"A little extra work never hurt anybody," Pestano said after his first save of the season and fourth of his career.
The win was Cleveland's sixth in 34 games since July 27 and came with Perez not even at the ballpark. He was with his wife Melanie, who delivered a baby girl earlier in the day.
"The bullpen was terrific," Indians manager Manny Acta said. "To stop these guys is huge. At any moment (the Rangers) can turn around the score."
Acta said he had no worries about putting Pestano in to pitch in the eighth inning with two outs and a runner on first.
"He was the best guy out there to stop the losing streak," Acta said. "We had to take care of the game today."
The Indians are just 12-36 since the All-Star break, with losing streaks of 11, nine and six games.
Texas entered with a four-game lead in the AL West over Oakland and lost for just the fifth time in 16 games.
"It's not always the best team that wins, it's the team that plays the best," Rangers manager Ron Washington said. "They put four runs on us in the first inning and they made it stand up."
Jeanmar Gomez (5-7) gave up three runs and four hits over 5 2/3 innings in his first start for Cleveland since June. He was recalled from Triple-A Columbus on Wednesday.
Cleveland tagged Scott Feldman (6-11) early and improved to 42-24 when scoring four or more runs.
"We had a lot of quality at-bats that inning," Acta said. "Then we allowed Feldman to get into a groove and he was dropping his breaking ball over the plate."
Feldman pitched shutout ball for his last five innings, but fell to 0-5 in five starts since Aug. 5.
"It was a nightmare first inning there," Feldman said. "They came out swinging and it seemed like everything they swung at they got some hits. I dug a little too deep a hole."
Adrian Beltre's 26th homer with two outs in the sixth made it 4-3 and finished Gomez.
Gomez opened the season in Cleveland's rotation and was 1-1 with a 2.35 ERA in four April starts before struggling and being sent to Columbus on June 24.
"He had a good sinker, good two-seam fastball, but the third time through the lineup, they started getting to him a little," Acta said.
Elvis Andrus hit safely against Cleveland for the 28th straight game, setting a Rangers record for a hitting streak against one team. Ivan Rodriguez had hit in 27 straight against Tampa Bay in 1998-2000.
Andrus extended the streak in his final at-bat in strange fashion. He took a big cut at a pitch from Rogers and sent a weak dribbler that hugged the third base line. It rolled foul at one point, weaved back into fair territory and Andrus laughed as he reached first base when the ball stopped at the third base bag.
Gomez started in place of Roberto Hernandez, out with a sprained right ankle. Hernandez left a start Monday because of the injury and tweaked it during fielding practice on Thursday. He will wear a protective boot for at least a week.
Cleveland also was without All-Star shortstop Asdrubal Cabrera, a late lineup scratch with a sore right wrist. Cabrera came in on defense in the ninth.
Russ Canzler, called up from Triple-A Columbus, went 2 for 4 as the DH in his Indians debut. ... Texas manager Ron Washington said he will try and get some playing time for prospect Jurickson Profar. When he does debut, the 19-year-old infielder will become the youngest Rangers player since C Ivan Rodriguez, also at age 19 in 1991. ... Washington wants to give Andrus some rest and used him as the DH. Andrus has missed only four games, starting 123 at shortstop. ... Cabrera has hit .103 over his past 11 games and .242 in the second half. ... Fans cheered as a member of the U.S. Navy Leapfrog team parachuted into the ballpark with the American flag during the national anthem.