HOUSTON -- Dexter Fowler delivered two critical insurance runs as part of his 3-for-4 performance and the Houston Astros held on for a 6-5 win over the Chicago White Sox on Saturday at Minute Maid Park.

After walking and scoring as part of the Astros' four-run first inning, Fowler smacked an opposite-field leadoff home run in the fifth before driving in right fielder George Springer with an RBI single in the seventh.

The Astros (15-28) needed the additional runs because the White Sox (21-23) rallied for two in the top of the eighth.

Right-hander Kyle Farnsworth, signed by the Astros on Saturday, surrendered a sacrifice fly to center fielder Alejandro De Aza and an RBI single to second baseman Gordon Beckham in his first appearance with his ninth club, enabling Chicago to shave a three-run deficit to 6-5.

Astros left-hander Darin Downs retired third baseman Conor Gillaspie to stall that rally with two runners on base. Right-hander Chad Qualls picked up his third save by retiring the White Sox in order in the ninth.

By holding on, the Astros made a winner of right-hander Jarred Cosart (3-3), who scuffled mightily through three innings yet righted his ship long enough to last five.

After nearly blowing all of the four-run lead his teammates provided in the first inning, Cosart stranded two runners in both the fourth and fifth to depart with a 4-3 lead.

Cosart allowed seven hits and issued four walks, but all three runs he surrendered came on outs, including two sacrifice flies in the second and a run-scoring groundout by designated hitter Jose Abreu in the third.

Houston jumped on White Sox right-hander Hector Noesi (0-4) with haste as second baseman Jose Altuve (single), Springer (RBI triple), Fowler and Castro (three-run home run) all reached before Noesi recorded his first out.

Noesi settled down but could not solve Fowler, whose run-scoring hits marred the remainder of his afternoon. Noesi departed after Springer singled to open the seventh, with the run charged to Noesi when Fowler greeted reliever Scott Downs with a single after Springer took second on a Noesi errant pickoff attempt.

NOTES: The Astros signed RHP Kyle Farnsworth on Saturday and optioned RHP Paul Clemens to Triple-A Oklahoma City. Farnsworth was 0-3 with a 3.18 ERA and three saves in 19 games with the New York Mets before being released on May 14. Clemens was 0-1 with a 4.08 ERA in eight appearances. ... The White Sox were pleased with the rehab performance of LHP Chris Sale on Friday night for Triple-A Charlotte (4 IP, 1 H, 0 ER, 2 BB, 11 Ks) but have yet to set a timetable for his return from the 15-day disabled list. ... Astros LHP Tony Sipp retired the side in the seventh inning, extending his string to 20 consecutive batters retired since signing with Houston on May 2.