J.A. Happ allowed three runs on six singles in the third inning, but threw well in a four-inning start vs. the Cardinals. (AP)

JUPITER, Fla. -- The Astros' four-run sixth inning off Cardinals reliever Adam Ottavino on Wednesday lifted Houston to a 4-3 road win in the first of two spring meetings between the two National League Central opponents.

Jed Lowrie and Brian Bogusevic started the sixth with hits before Ottavino walked Jack Cust to load the bases. Travis Buck and Brett Wallace both collected RBI hits later in the inning. Jason Castro drove home another with a sacrifice fly. Four of the Astros' seven hits on Wednesday came off Ottavino.

A slew of singles had helped the Cardinals jump out to an early advantage. Six of them -- five with two outs -- came off Houston starter J.A. Happ in the third inning. Three runs scored on RBI hits by Matt Holliday, David Freese and Yadier Molina. Holliday finished the game with three hits. Jon Jay, Freese and Molina also enjoyed multihit games for St. Louis.

Happ rebounded to pitch a perfect fourth, which was his final inning of work. He allowed seven hits, none for extra bases, and struck out three. Happ, who threw 51 of his 68 pitches for strikes, did not allow a walk.

"It's coming along," Happ said. "I couldn't see what the velocity was. I wasn't watching for that, but I think it's on its way."

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Lance Lynn was even better, providing the Cardinals with three scoreless innings in his first Grapefruit League start. Expected to be a key member of St. Louis' bullpen this season, Lynn was recently told that he will transition back into a starter's role until the Cards have a better grasp on how long Chris Carpenter's season could be delayed due to a neck issue.

Lynn allowed a pair of one-out singles in the first and then retired the final eight batters he faced. He struck out three, walked none and threw 29 of his 40 pitches for strikes. Lynn had pitched just three innings in his first two spring appearances combined.

"You always want to have that opportunity to be a starter, long-term," Lynn said. "But the way I see it is, wherever they want me to pitch, whatever is going to make me successful and win a lot of games, it doesn't really matter where it's at."

Scott Linebrink, who is fighting to earn a spot in the Cardinals' bullpen as a non-roster player, did not allow a hit in his 1 1/3-inning appearance. Mitchell Boggs also had a scoreless outing for St. Louis.

Houston relievers Juan Abreu and Paul Clemens did not allow a run in their appearances.

Up next: Zach Duke is scheduled to take the mound for the Astros on Thursday, when they host the Blue Jays at 12:05 p.m. CT in Kissimmee, Fla. Duke's last outing also came against Toronto, which knocked the lefty around for six hits and three earned runs in four innings. The Blue Jays will send Dustin McGowan to the hill for the start.