JUPITER, Fla. -- Riding a six-run first inning that was highlighted by Oscar Taveras' grand slam, the Cardinals ran their win streak to four with Thursday's 8-2 victory over the Marlins at Roger Dean Stadium.

The Cardinals chased Marlins starter Jacob Turner before the St. Louis-area native could finish an inning in his first start of the Grapefruit League season.

Turner struggled with his command from the get-go. He walked two and hit Carlos Beltran on the right foot with a pitch to load the bases for Yadier Molina, who drove in one with a single. Taveras, ranked by MLB.com as baseball's No. 3 prospect, followed with a grand slam over the right-field wall.

The next three Cardinals reached base as well, prompting Marlins manager Mike Redmond to pull Turner after one-third of an inning.

It wasn't all positive for the Cardinals, though, who had to pull Beltran and starter Jake Westbrook prematurely due to injuries. Beltran didn't return to the outfield after running the bases in the first. In the top of the second, Westbrook was struck on the inside part of his left knee by a comebacker. After a lengthy mound conference, he, too, walked off the field.

Westbrook was diagnosed with a left knee contusion. He said afterward that he would have lobbied to keep pitching had it been a regular season game.

"It hurt pretty good at the time, but once I was able to walk it off a little bit, I could have easily kept going," Westbrook said. "It's precautionary."

Westbrook, who was making his first spring start, allowed four hits and one run in his inning of work. Tyler Lyons relieved him and tossed two scoreless frames. Trevor Rosenthal, who is competing for a rotation spot, followed with a three-inning appearance. Rosenthal allowed one run on two hits and a walk.

Miami's bullpen halted the Cardinals' offensive production upon Turner's exit. Kevin Slowey, who is in the mix for a job in the Marlins' rotation, allowed only one hit in 2 2/3 innings. Right-handers Sam Dyson and Evan Reed followed with scoreless appearances.

Marlins outfielder Giancarlo Stanton went 3-for-3 with a single, double, triple and two runs scored.

Up next for the Marlins: Henderson Alvarez on Friday will make his second, and last start for a while, for the Marlins in Spring Training. The right-hander takes the mound vs. the Twins at Roger Dean Stadium. On March 3, Alvarez will leave the Marlins to play for Venezuela in the World Baseball Classic. Vance Worley gets the start for Minnesota.