An elevated heart rate from Niese that popped up in the fourth inning after he singled and rounded the bases to score forced Collins to call on his bullpen for the first time in the four-game series against the defending World Series champions.
Collins said Niese would be checked out by doctors Monday as a precaution, but the starter did not seem concerned. He experienced the same issue in a start last season in Texas, wore a heart-rate monitor in his following start and has been fine since.
He left the game after only 96 pitches, but he was happy with his start.
"It's one of those things where I threw six solid, scoreless innings," said Niese, who watches Santana's starts from the clubhouse to track his pitches and see how he attacks hitters. "I kept feeling the heart racing at times. I felt that was enough. I didn't want to do anything stupid, but I feel fine now and that's a good sign."
By the time the Mets' bullpen door opened for the first time and Bobby Parnell trotted across the outfield to toe the rubber, New York had a six-run lead.
That cushion came courtesy of a three-run sixth inning, spearheaded by top-of-the-order outfielders Kirk Nieuwenhuis and Andres Torres. Nieuwenhuis singled in Omar Quintanilla from second and Torres followed with a two-run triple deep into the right-field corner.
It was one of three hits on the night for Torres, who doubled in the first inning and scored the Mets' first run. He fell a homer shy of the cycle as he returns to his expected role as an everyday player with Mike Baxter on the disabled list.
"He's got to get on, he has to get on for us," Collins said. "When Andres gets on base, he scores. He's in scoring position and can score on a single. He can steal bases. That's what we're looking for. We need him to continue what he's doing right now."
But the Mets have rolled along with injuries all season by receiving contributions throughout the lineup, with no better example than Nieuwenhuis.
The left fielder, whom the Mets called up on the second day of the season when Torres landed on the DL, set a career high of three RBIs with his RBI single and two-run homer a day after Collins said the rookie may have seen his final days in the Minor Leagues. Now, Collins is wondering how to work his lineup with the impending return of injured outfielder Jason Bay.
"We're going to have to figure out something," Collins said. "Certainly we're very happy with the way Kirk's playing, but we have to get Jason back here and get him in the lineup. We'll have some fun decisions to make as we go down the road here."
Recent callup Elvin Ramirez allowed the lone St. Louis run in the eighth inning, when Adron Chambers singled to center field with Freese on second base for the second time of the night. Torres came up throwing in the sixth and beat Freese home in a play at the plate, but there was no throw in the eighth.
It mattered little as the Mets moved into a tie for first place.
"I think that you have to give credit to their pitchers," Cardinals slugger Matt Holliday said. "Johan is obviously an established pitcher and he pitched very well. Dickey is kind of a trick deal and he's obviously 8-1 with a [2.69] ERA. I've always thought that Niese is kind of underrated. I have to give credit to that they've just pitched very well."