John Buck is the Mets’ equivalent of NCAA Tournament shocker Wichita State.

The veteran catcher has emerged from obscurity this spring, and last night Buck continued his sensational start to 2013. He smashed a three-run home run deep into the right-field stands off Roy Halladay, handing the Mets an early lead and helping to back Matt Harvey to a 7-2 win over the Phillies.

Through seven games, Buck is hitting .375 (best among Mets regulars) with three homers (also tops on the team) and 12 RBIs (more than double anyone else on the club). That’s more than a decent start to the year.

“It feels like I’m doing what I’m capable of doing,” Buck said.

Buck entered the season a .235 hitter over his nine years in the majors with Kansas City, Toronto and Miami, although he had smacked 16 or more homers in three different campaigns. But in terms of run production this year, Buck has gone wild. He has driven in 60 runs just once in his career, when he plated 66 in 2010 with Toronto.

Is Buck surprising people with his offensive output? He shrugged when asked the question.

“I don’t really care,” he said. “I figure if I just keep doing what I’m doing, they can be surprised at the end of the year.”

Halladay may have been surprised last night. In 22 previous career at-bats against the Phillies righty, Buck had managed just four hits — all singles — and had struck out seven times. Granted, Halladay may not be the ace he used to be any more, but Buck had barely ever done anything off him.