(JEFFREY PHELPS ~ Associated Press)
The Cardinals' Matt Holliday left the game after getting hit in the leg with a pitch in the first inning, and Brewers slugger Ryan Braun was removed with a right adductor strain in the seventh. St. Louis' Lance Berkman was ejected for arguing a call.
Brewers manager Ron Roenicke gave the closer's job to Rodriguez before the game with John Axford continuing to struggle.
It wasn't easy for Rodriguez, who allowed the first two batters to reach before nailing down his second save this season.
Wolf (3-6) went 6 2/3 innings. He gave up two runs and eight hits with a walk and six strikeouts.
Cardinals starter Joe Kelly (1-2) took the loss.
Rodriguez gave up a leadoff double to David Freese, then a single to Yadier Molina to put runners on first and third with no outs.
Rodriguez then got Matt Carpenter to ground out, holding the runner at third, and struck out pinch-hitter Skip Schumaker. With runners on second and third, Rodriguez got pinch-hitter Daniel Descalso to pop up to end the game.
Wolf hasn't had a victory since April 30 at San Diego, but the Brewers' bullpen shares some of the blame for his winless streak. Coming into Tuesday's game, Wolf was 0-4 with a 5.45 ERA during his last 12 starts. He left seven games with the lead, only to have the bullpen blow it during that stretch.
Kelly went six innings. He gave up three runs, two earned, with six hits, a walk and four strikeouts.
Holliday took an 89-mph fastball from Wolf off his left leg in the first inning. Holliday remained in the game after spending several minutes with the team's trainer. But Cardinals manager Mike Matheny took him out in the bottom of the second, when Jon Jay came in as a defensive replacement. Holliday's injury was described as a left thigh contusion.
The Brewers took a 1-0 lead in the first on an RBI single by Corey Hart.
But the Cardinals came back with two runs in the third when Rafael Furcal took a one-out walk, Allen Craig singled and Jay hit an RBI double. Craig then scored on a sacrifice fly by Carlos Beltran, but Jay was thrown out while trying to take third.