The crowds have been small at Tradition Field this spring, and for the most part, they also have been pretty quiet.

Yesterday, all it took to get Mets’ fans attention was 4 1/3 innings of no-hit ball from Matt Harvey.

The right-hander overmatched an admittedly weak Miami lineup in a 4-1 win and left after 48 pitches to the loudest ovation anyone has heard this spring.

“He’s on a mission to be real good,” manager Terry Collins said after Harvey struck out five, walked none and allowed just one base-runner on an Omar Quintanilla error at short. “Matt went out and set on a tone, and all of a sudden, everything else fell into place.”

Already armed with a major league arsenal, Harvey still is in the process of adding a changeup to go along with his three other pitches. Even his newest pitch was effective yesterday.

“Today was the first day I’ve been able to bring what I’ve been working on in the bullpen onto the mound,” Harvey said of his third start of the Grapefruit League season. “It felt good.”

But he wasn’t interested in his stat line.

“I was just getting the work done,” Harvey said.