Manager Jerry Manuel said Wagner, who has a muscle spasm around the joint, would be a midgame decision based on how the left-hander felt.
Dauner Sanchez gave up three straight hits to start the ninth.
Joe Smith (1-2) relieved and Carlos Ruiz drove in a run with a high bouncer that shortstop Jose Reyes fielded but he missed stepping on second base.
Pedro Feliciano came on and Taguchi, a pinch-hitter, stroked a two-run double to tie it. Rollins followed with a double that made it 7-5. After an intentional walk to Pat Burrell, Ryan Howard hit a ball back to Feliciano but he had trouble fielding it and could only get one out allowing another run to score.
Chad Durbin (3-2) pitched a perfect eighth, and Brad Lidge gave up a run in the ninth but finished for his 22nd save in as many chances.
The Phillies, who entered hitting just .248 over the last 13 games when they went 6-7, could have had a much bigger deficit to make up had they not made two big defensive plays in the seventh.
Right fielder Jayson Werth threw out Endy Chavez at home on a hit by David Wright, and second baseman Chase Utley made a diving grab of pinch-hitter Fernando Tatis' liner with the bases loaded to end the inning.
The last time Santana faced the Phillies on July 4, he gave up two runs in eight innings but the Mets lost 3-2. On Tuesday, he allowed an RBI single to Werth in the first and Shane Victorino's homer in the seventh after he retired 15 of 16 batters. He had four strikeouts, including the 1,500th of his career.
The Mets took a 5-1 lead against Joe Blanton behind Carlos Delgado's 450th career homer, a two-run shot, Raul Castro's two-run homer and Wright's RBI double in the second. Chavez was thrown out at home on a nice relay started by left fielder Burrell.
Blanton was making his first start for the Phillies since being acquired from Oakland last week to solidify a shaky rotation. He took the spot of Adam Eaton, who was 3-8 with a 5.71 ERA.
Blanton came in having thrown 15 shutout innings against the Mets in two starts for the A's and he looked as if he were pitching to form until he walked Jose Reyes on four pitches to open the third. He gave up five runs and eight hits in six innings.
Phillies manager Charlie Manuel was ejected by third base umpire Marty Foster after the third inning. Manuel started yelling at Foster when he ruled Delgado did not go around on a half-swing before his homer and carried on with the argument after the final out. It was his third ejection this season.
