Mets pitcher Johan Santana delivers in the second inning against...

Mets pitcher Johan Santana delivers in the second inning against the San Diego Padres. (May 26, 2012) Credit: Kathleen Malone-Van Dyke

It all starts with Johan Santana. The credibility that the Mets have developed this year, and that is a lot more than they were expected to have, begins with their No. 1 starting pitcher. Of course, Santana is more than just a No. 1. He is a true ace.

There is a distinction. An ace is someone who gives a team personality and confidence. An ace is someone who affects everyone else. An ace is someone who can quietly dominate a game, as Santana did with a four-hit shutout in a 9-0 win over the Padres at Citi Field Saturday.

"You see what he's just done with this team in the last 40-some-odd, 50 games. It's incredible. He's a huge presence for us," said Mike Nickeas, who caught Santana and supported him with a grand slam in the eighth. "It just goes to show you how we can roll when a guy like that takes the ball."

Scott Hairston, whose three-run shot in the first inning was the first of the game's three "new Citi" home runs that benefited from the park's hitter-friendlier dimensions, said, "I think it's character and confidence. The way he came out today, there's a certain presence about him. When he has his stuff, he's very hard to hit, and that's very intimidating to the opposing team. It lifts everybody up. It makes you want to support him."

Santana inspires the Mets in various subtle ways. David Wright said he was impressed by the pitcher's work ethic when the two teammates were rehabbing injuries in Florida last season. Mets manager Terry Collins pointed out that the ace gave a tutorial to fellow starter Jon Niese recently "and Jon Niese goes out there and spins the best game he has had all year long."

But mostly, Santana lifts the club with his pitching. He retired 16 in a row between the second and seventh, and the Padres never had more than one runner on base in any inning. Santana (2-2) walked none and struck out seven. He threw 74 strikes among his economical 96 pitches for his 14th complete game.

He achieved the ninth shutout of his career and his first since Aug. 12, 2010. Notably, it was his first since shoulder surgery a month and two days after that previous shutout.

"It's a great feeling for me, just to put my uniform on and be part of my team. It's amazing," he said. "Now, being able to help and being able to go out there every five games, it's definitely something that I was waiting for. I'm very happy for it. I'm just going to continue doing it."

He acknowledged that it was not quite as complete a game as one might think. His right (non-pitching) side was sore, which affected him when he was at the plate. "I didn't want to do anything crazy," Santana said. "I wasn't trying to hit at all. I was just trying to take everything easy. I was just trying to pitch because that's my job."

Other guys did the hitting. Vinny Rottino completed a four-run first against Clayton Richard (2-6) with his first career home run. Ike Davis drove home a run with a pinch double.

"You understand that if you put up a few runs early, the game is over," Wright said.

The best measure of an ace is that he can make a team believe in itself. The Mets are 26-21 and do not consider it a fluke. "We are," Nickeas said, "capable of a lot more than people give us credit for."