Kansas City, Mo. ? Chris Carter hit two home runs, George Springer set a rookie club record for homers in a month, and the Houston Astros beat the Kansas City Royals, 9-3, on Wednesday for their fifth straight win.

The Astros, with the worst record in the AL, won three times in Kansas City for their first sweep of the season. Houston’s winning streak is its longest since a six-game string that ended last June 3.

The Royals have lost four in a row.

“It’s just a bad series. Unfortunately, it happened at home,” Royals designated hitter Billy Butler said. “It’s a tough go right now.”

Carter, been benched the previous three games with a .192 batting average, homered to lead off the fifth. He hit a three-run homer in sixth off reliever Louis Coleman for his fourth career multihomer game and his first this season.

Springer homered off Danny Duffy (2-5) in the first for his ninth home run in May. Glenn Davis held the Astros’ rookie record with eight home runs in September 1985.

Carlos Corporan had three hits with a walk. He drove in a run as the Astros outscored the Royals 21-5 in the series.

Jarred Cosart (4-4) gave up one earned run and four hits in five innings.