San Diego, CA (SportsNetwork.com) - Colby Rasmus homered and drove in three runs, and the Houston Astros pulled out a 9-4 win over the San Diego Padres in the opener of a three-game series on Monday.

Jed Lowrie and Jason Castro each added solo homers for the Astros, who have won four straight and eight of their last nine overall.

Houston has won all four starts this season by Collin McHugh, who threw another quality outing but did not factor in the decision. The right-hander allowed three runs on seven hits over six innings.

Wil Myers and Yangervis Solarte both knocked in a pair of runs atop San Diego's lineup, while James Shields struck out 12 over six innings in a no- decision. San Diego's offseason acquisition gave up three runs -- one earned -- on six hits.

"His stuff was good. He pitched well," Padres manager Bud Black said of Shields. "He had a legit curveball."

Joaquin Benoit (3-1) faced four batters in the eighth and did not record an out as the Astros broke a 4-4 tie with three runs.

George Springer and Lowrie both walked, and a double steal resulted in Derek Norris' throw to third sailing into left field, allowing Springer to score the go-ahead run. Rasmus and Chris Carter followed with RBI hits, and Rasmus cracked a two-run homer in the ninth to cap the victory.

"I wouldn't have guessed a 9-4 game after the way the starting pitchers pitched the first third of the game," Astros manager A.J. Hinch said.

Shields coughed up a towering blast to Lowrie in the fourth and would have gotten out of the fifth unscathed had Alexi Amarista not committed an error on Jake Marisnick's steal of second. Marisnick scored when Jose Altuve one-hopped the fence in center for a ground-rule double, and Luis Valbuena followed with an RBI single for a 3-0 Astros lead.

McHugh was one strike away from escaping the fifth several times, but the Padres pushed three across to even things. Shields kept the inning alive with a single to put runners on the corners, and Myers hit a line drive to left that was just out of Colby Rasmus' reach. Two runs scored on the double, and Myers came around on Solarte's bloop single to left.

Castro took Brandon Maurer deep leading off the seventh, and the Padres got the run back in the bottom half on Solarte's RBI double. Pat Neshek (1-0) got out of a two-on, one-out jam thanks to Altuve throwing out Myers at home on a ground ball hit by Kemp.

Game Notes

The Astros are 10-0 when scoring first and 11-0 when scoring at least four runs ... Lowrie exited in the eighth with a right thumb injury ... Both teams recorded 10 hits.