Stephen Piscotty's throw from right field reached Yadier Molina far too late. Gregory Polanco slid home with a flourish, turned around and smacked the plate with his left hand. Mercer was so locked in on his at-bat that he didn't even know it was the speedy Polanco on second, but he knew his hit was enough to end a long, cold night at PNC Park.
"It feels great," Mercer said. "Definitely feels great."
So, too, does Mercer's fast start at the plate.
Mercer entered this season looking to get out of the gates better than he has each of the past two years. He hit .167 in March/April 2014. He hit .197 in April 2015.
The season is only two games old, but already Mercer can tell a difference. He hit an RBI double to center field and drew a walk on Opening Day. On Tuesday, he went 2-for-5 with two strikeouts. It's taken him two games to drive in a pair runs; last year, he was stuck on four RBIs through his first 24 games.
One possible cause of Mercer's early success? Look back to Spring Training. His Grapefruit League numbers (.275/.275/.353) may not mean much, but his mindset did.
"It's a little cliché, but it's kind of the first time I really didn't have to fight for a position. I was able to work on some things and see some pitches and do some different things," Mercer said. "It was a different Spring Training for me, and I think it's leading into the season as well."
The Pirates don't need Mercer to hit .300 or drive in 75 runs this season, especially not when he's batting eighth against right-handed starting pitchers. But their lineup becomes much deeper when he's hitting well, and there's no better proof than how the 11th inning unfolded Tuesday night.
"Time will tell. Nothing breeds confidence like success," manager Clint Hurdle said. "He had a big hit the other day, drove a ball in the gap, drove in a run. Couple hits tonight, game-winner. It's good to see."
Adam Berry is a reporter for MLB.com. Follow him on Twitter at @adamdberry. This story was not subject to the approval of Major League Baseball or its clubs.