HOUSTON -- For every three strikeouts that lead to questions about the logic behind Houston Astros manager A.J. Hinch penciling first baseman Chris Carter into the lineup, Carter delivers one swing to validate the decision.

Carter belted a go-ahead, three-run homer in the sixth inning and the Houston Astros rallied for their fourth consecutive victory Saturday night, a 6-5 win over the Toronto Blue Jays at Minute Maid Park.

Carter struck out three times in four at-bats and will enter the series finale against Toronto batting just .158 this season. However, his sixth home run of the season, an opposite-field shot off Blue Jays right-hander Liam Hendriks, delivered the Astros their first lead of the game.

"Tonight is a great illustration of why he belongs in the lineup," Hinch said of Carter. "He can impact a game any given second. There's not a pitch that goes by when he's up to bat that both dugouts don't know that this guy can make a difference in the game."

While Carter swung momentum in the Astros' favor, left-handed-hitting outfielders Preston Tucker and Colby Rasmus deserved equal credit for igniting the rally against southpaw Jeff Francis (1-2).

Tucker greeted Francis with a leadoff single to right field and Rasmus followed with a double to center that advanced Tucker to third and set the table for Carter, whose blast pushed the Astros (24-13) to a 5-3 lead.

Two batters later, shortstop Marwin Gonzalez added a solo homer, his second home run of the season, for what proved to be a crucial insurance run.

Astros right-hander Luke Gregerson picked up his ninth save despite surrendering a two-run, two-out homer in the ninth to pinch-hitter Edwin Encarnacion.

Including designated hitter Evan Gattis' two-run homer in the third, the Astros have an American League-leading 55 homers this season.

The rally made a winner of right-hander Scott Feldman (3-4), who struggled in the first inning yet recovered to pitch into the seventh. Feldman had a season-high 10 strikeouts and allowed just two hits after the Blue Jays (17-21) jumped out to a 3-0 lead in their first at-bat.

"The guys swung the bats great and the defense was good," Feldman said. "The bullpen came in, did their thing, (Astros catcher) Hank (Conger) called a great game back there. Happy to get the win tonight."

Feldman has allowed 11 of his 28 runs in the first inning this season, a trend that continued when the Blue Jays sandwiched two extra-base hits around a walk.

Third baseman Josh Donaldson reached on a double and scored when catcher Russell Martin followed a Jose Bautista walk with a two-run triple to center. First baseman Justin Smoak added a sharp single to right that scored Martin for a 3-0 lead.

"We got off to such a quick start, you felt really good," Blue Jays manager John Gibbons said. "(Houston) hung close and opened it up late with the homers."

Feldman retired the side in order in the third, the start of a stretch where he retired 12 of 13 batters, including striking out the side in the fifth.

Blue Jays right-hander Marco Estrada had his hiccup in the third, issuing a leadoff walk to Astros second baseman Jose Altuve and later surrendering a two-run homer to Gattis.

But like Feldman, Estrada was occasionally dominant in his five innings, walking four but also fanning eight, and matching Feldman by striking out the side in his final inning.

"The good thing is stamina-wise I felt pretty good," Estrada said. "Felt like I could have gone out for another inning."

NOTES: The Blue Jays acquired 1B/DH Luke Scott from Puebla of the Mexican League for cash and assigned him to Triple-A Buffalo. Scott last played for the Tampa Bay Rays in 2013. In his nine-year major league career, Scott hit .258/.340/.481 with 135 home runs and 436 RBIs in 889 games with the Rays, Houston Astros and Baltimore Orioles. ... Astros LF Preston Tucker earned his third consecutive start after becoming the first rookie in club history to post multiple doubles in back-to-back games. Tucker was 5-for-8 with four doubles in the first two games of the Toronto series. ... Blue Jays 1B Edwin Encarnacion was not in the lineup for the first time this season. Starting in his place was Justin Smoak, who entered the game hitting 5-for-11 with two home runs and three walks against Astros RHP Scott Feldman.