(Sports Network) - A pair of aces square off this afternoon at Citi Field, where Chris Carpenter will lead the St. Louis Cardinals against Johan Santana and the homestanding New York Mets in the finale of a four-game series.

Carpenter is 5-1 with a 1.53 earned run average in nine starts this season, and 4-1 in five decisions since coming off of the disabled list in May because of a strained oblique muscle. He last pitched on Saturday in a 7-1 win at Kansas City and picked up the victory with 7 2/3 innings of one-run ball. He scattered three hits, struck out six and walked two batters.

The right-hander improved to 2-1 in six road starts this season and will toe the visiting mound once again in New York. He is only 1-3 with a 5.09 earned run average through four career starts against the Mets.

The oft-injured Carpenter made only one start in 2007 and that was versus the Mets on April 1 at Busch Stadium. He was dealt the loss for allowing five runs and nine hits over six innings of a 6-1 defeat.

St. Louis hopes Carpenter can get it back in the win column after suffering an embarrassing 11-0 loss in Wednesday's third test of this four-game set. Brendan Ryan finished with two of the four hits for the NL Central-leading Cardinals, who had won four of their past five games entering the game. Starting pitcher Brad Thompson may have lost his bid to remain in the rotation after he allowed five runs on eight hits and one walk in five-plus innings.

"This is obviously a bad game for us. We got it out of our system. I need to set the tempo out there," Thompson said. "We didn't score any runs today. It's one of those days."

Thompson is taking the place of injured starter Kyle Lohse.

The Cardinals are 4-2 on a seven-game road trip and now sit just one game ahead of Milwaukee in the division standings.

New York pulled within 1 1/2 games of the Philadelphia Phillies for the top spot in the National League East after last night's pummeling of the Cardinals, coupled with Philly's loss in Tampa Bay. David Wright ended with four hits in as many plate appearances and three runs scored, while Ryan Church had three hits -- including two doubles -- two RBI and a pair of runs in the win, just the Mets' third in their last eight games.

Nick Evans belted a two-run homer and Fernando Tatis drove in three runs on two hits for the Mets, who are 3-3 on a 10-game homestand versus the Rays, Cardinals and Yankees. The Bronx Bombers are slated to visit Citi Field this weekend.

New York starter Fernando Nieve improved to 3-0 in Wednesday's win and gave up just three hits with five strikeouts and four walks in six frames.

"He goes out there and has a game plan and knows what he wants to do. He really goes out there and gives you a great effort," said Wright about Nieve.

Mets ace Johan Santana needs a great effort today and is caught in a rare funk, having lost two straight and three of his last four starts with a 7.33 earned run average over that span. His current two-game slide began on June 14 at the new Yankee Stadium, where he was rocked for nine runs and nine hits in three innings of a 15-0 debacle.

Santana then took the mound on Saturday versus Tampa Bay, only to lose another start after yielding two runs and three hits in 7 1/3 innings of a 3-1 setback. He is 8-5 with a 3.22 ERA in 14 starts this season, but must turn things around for New York's struggling rotation.

The left-hander and two-time Cy Young recipient is 5-2 in eight home starts this season and will face St. Louis for the second time in his career. Santana tossed a complete game in his only appearance against the Cardinals on July 27 of last season, holding them to a run and six hits with five K's and one walk.

The Cardinals swept the Mets in three games at Busch Stadium from April 21-24 and have won five of the last eight meetings between the teams.