Miami went 21-8, setting a franchise record for victories in a month.
Of course, there was some timely hitting throughout the month, especially from Giancarlo Stanton, who belted 12 homers and drove in 30 runs in May.
But it was the starting pitching that lead the way, going 15-7 with a 3.53 ERA.
"I think the biggest reason we are where we are is because of our starters," manager Ozzie Guillen said. "That's not doubt. Our starters make our bullpen look good. Maybe a few games we've had to overwork our bullpen, but I think our starters have meant a lot."
The 15 wins were the most by any rotation in the National League, and only the Dodgers' collective ERA of 3.36 was better than Miami's ERA.
"We've pitched well," Guillen said.
Guillen feels his rotation has stacked up with everyone in the NL.
"We don't have anybody missing games," he said. "We don't have anybody that we have to give a day for missing a start. That means a lot to for us."
Miami's rotation threw 188 2/3 innings, matching the Phillies for the most in the NL in the month. And there were two complete games, which also matched the high of any team.
"If you don't have good starters in baseball right now, you're going to have problems winning games," Guillen said. "If your starters do what they're supposed to do, you're going to have a chance."