(Sports Network) - Right-hander Brad Thompson starts against the Cincinnati Reds for the second time this season today when the St. Louis Cardinals head to Great American Ball Park for the middle test of a three-game series with their National League Central Division rivals.

Thompson, who entered 2009 with just 24 starts in 153 big-league appearances, began this season with nine straight outings out of the bullpen before getting a start against the Reds on June 2.

He went five innings in the Cardinals' 5-2 win, getting a no-decision after giving up five hits and two runs in five innings.

Since, he's 2-3 in five starts, allowing 16 earned runs in 28 1/3 innings.

For Cincinnati, resurgent No. 5 starter Micah Owings seeks a third win in four starts.

The 26-year-old Georgian was 3-7 after losing four straight starts between May 16 and June 5, before toppling Atlanta, 4-3, on June 17.

He dropped a 7-5 verdict at Toronto six days later, but recovered again in the northeastern portion of the "Battle of Ohio," defeating the Cleveland Indians, 8-1, with six innings of five-hit, one-run ball.

Owings got a no-decision in his lone career start against the Cardinals while with Arizona, giving up four hits and seven runs - two earned - in 2 2/3 innings.

The Cardinals enter the day in sole possession of first place in the tightly- bunched NL Central, leading second-place Milwaukee by a game, while the Reds sit fourth in the six-team loop, three games behind.

On Friday, Jarrett Hoffpauir came through in a big way in his major league debut, hitting the go-ahead two-run single in the ninth inning, lifting St. Louis to a 7-4 win.

Fresh off being named NL Player of the Month, Albert Pujols belted his fourth grand slam of the season in the eighth inning and knocked in five runs over the final two frames. He upped his major league- leading totals to 31 homers and 82 RBI.

Jerry Hairston Jr. had three hits and an RBI for the Reds, who had won four of five coming into the weekend.

Reds starter Homer Bailey had a strong outing, yielding three hits and two runs over 7 1/3 innings, while St. Louis' Joel Pineiro allowed eight hits and three runs -- two earned -- in seven frames.

Nick Masset was on the mound for the top of the ninth, but left after taking a ball of his arm. Danny Herrera (1-4) then relieved Masset and retired Joe Thurston on a pop-up, but Colby Rasmus and Brendan Ryan singled and Skip Schumaker was safe on an error by shortstop Paul Janish, a ball that he couldn't handle on a short hop.

Then, in his first official big league at-bat, Hoffpauir smacked a soft liner to left field. Hoffpauir, a sixth-round draft pick by the Cardinals in 2004, was called up Wednesday from Triple-A Memphis and became the 15th rookie to appear with St. Louis this year.

Pujols then greeted reliever Carlos Fisher with an RBI double down the left- field line.

It was a tenuous bottom of the ninth, but Ryan Franklin was able to pick up his 20th save of the year. Edwin Encarnacion doubled with one out, and Willy Taveras walked with two down, putting runners at the corners. Joey Votto walked before Brandon Phillips struck out to end the game.

Cincinnati has split its eight meetings with the Cards this season.