ST. LOUIS(AP) Rookie Rick Porcello beat the heat and the St. Louis Cardinals, whose starter had to be carried off the field.

Porcello won for the seventh time in nine starts while pitching in 90-degree heat and the Detroit Tigers shook off an offensive drought with a four-run first inning in a 6-3 victory on Thursday that avoided a three-game sweep.'

''It was a real good win for us because we were probably ripe for the sweep, to be honest,'' manager Jim Leyland said. ''A long, grueling trip. It would have been easy to say 'Let's go home, it's been a long trip.'''

Placido Polanco and Marcus Thames homered in the eighth for the Tigers, who had scored three or fewer runs in their previous seven games. Detroit ended a four-game losing streak and won for the first time in six games at 4-year-old Busch Stadium counting three losses to end the 2006 World Series.

''It was huge,'' said Gerald Laird , who had an RBI double in the first. ''We've been struggling with the bats for a while now and to come out and get a couple of hits was a good sign.''

Porcello (8-4) allowed three runs in 5 2-3 innings. He worked out of trouble in the first, second and fifth, stranding two runners in each inning and is 7-1 with a 2.64 ERA in his last nine starts.

''I thought I threw the ball OK,'' Porcello said. ''I left a couple of fastballs up but the changeup was really good and bailed me out of a couple of situations where I thought it could have been a lot worse.''

The right-hander leads AL rookies in wins and is 3-0 with a 1.45 ERA in three interleague starts. Fernando Rodney , making his first appearance in six days, walked the bases loaded with one out in the ninth before inducing a double play ball from Rick Ankiel for his 13th save in 13 chances.

Cardinals starter Joel Pineiro made a dramatic exit, cramping in his right leg and collapsing in front of the mound after striking out Josh Anderson to end the seventh. Pineiro, who allowed one earned run but left trailing 4-3, was carried off the field by Ankiel and Yadier Molina after failing in an attempt to reach the dugout on his own.

''I felt embarrassed,'' Pineiro said. ''I tried to walk it off but I couldn't get up and I fell right back down,'' Pineiro said. ''I said 'It hurts too much, just get me in there fast.'''

Pineiro (5-8) allowed four runs and four hits in the first, then retired 16 in a row starting with the last out of that inning. He gave up only one more hit, a leadoff single by Brandon Inge in the seventh.

Khalil Greene , activated from the 15-day disabled list for social anxiety disorder earlier in the day, struck out as a pinch hitter in the eighth.

The Tigers opened the game with singles by Curtis Granderson and Polanco, and four players had an RBI apiece. Only one of the runs was earned after third baseman Joe Thurston booted Miguel Cabrera 's RBI grounder.

A wild throw on Pineiro's poor bunt by Laird, the catcher, handed the Cardinals a run in the second and Tyler Greene added an RBI infield hit to cut the deficit to 4-2. St. Louis parlayed two hits and Chris Duncan 's RBI infield grounder to cut the gap to a run in the fifth.

NOTES: Cardinals manager Tony La Russa won his 100th game against the Tigers on Tuesday and is in triple figures against 16 teams, by far the most in major league history according to the Elias Sports Bureau. ... Hall of Famer Lou Brock attended the game on his 70th birthday. ... Magglio Ordonez , benched ''indefinitely'' by Leyland, is a .409 career hitter (9 for 22) against Pineiro. ... Albert Pujols grounded out as a pinch hitter for hot-hitting rookie Colby Rasmus in the seventh and played first base the rest of the game and flied out in the ninth. ... Pineiro is 6-2 with a 2.66 ERA against the Tigers, lowest against any AL opponent. ... The homers by Polanco and Thames came off rookie RHP Jason Motte , who has surrendered four homers in his last six appearances over 3 2-3 innings.