There has been an ongoing debate for much of this season over who is the ace of the Red Sox pitching staff.

Last night for at least one night Jon Lester ended the discussion.

Lester was nothing short of brilliant in Game 1 of the World Series pitching 72⁄3 innings of shutout ball by mixing his pitches the way Pablo Picasso mixed his paints.

On nearly every at-bat he had the St. Louis Cardinals’ hitters off balance never quite sure what to expect next except for something they couldn’t hit. The more aggressively they tried to attack him the more he left them baffled and bewildered.

If the situation called for a fastball a breaking pitch appeared. Looking for a curve? A backdoor cutter shows up and you’re frozen where you stand. It was that kind of night for the Cards who fell behind early and had no answers all night to the questions Lester was asking as the Sox cruised to a 8-1 win at Fenway Park and a 1-0 lead in the Series.

“We kind of expected it” Lester said of St. Louis’ early aggressiveness at the plate. “We know how aggressive they can be at times. Late in the game they tried to slow some things down and take some pitches after that so we wanted to set the tone and get them swinging.

“That’s important for my game as far as getting that fastball and cutter involved and making sure they’re not able to just lock in and key on certain areas on me.”

The Cards never did primarily because Lester was making pitches that left them always wondering often doubting never self-assured as Lester struck out eight and got the leadoff man in every inning but the fourth which was really the only shaky moment he faced.

In that inning he walked Jon Jay and then after striking out Matt Holliday gave up consecutive singles to Allen Craig and Yadier Molina to load the bases. This was the moment of truth. The moment an ace finds a way and a joker finds the showers.

Lester quickly proved to be the former snagging a ground ball back at him from David Freese and turning it into a double play with the help of his co-conspirator all night catcher David Ross.

“It was big” Lester said of his escape act. “Obviously with us scoring some early runs there just wanted to especially in the middle innings get some shut-down innings and get the guys back in the dugout. That one got a little away from me but was fortunate enough to get a pitch down to Freese there and get a ground ball. Rossy did a great job of making sure that we got the first one at home and then made a good throw to Nap(oli at first). That was obviously a big inning for us . . . to shut that down and not let any runs score.”

No one knew that better than Cardinals manager Mike Matheny. For him it was a long and frustrating evening made worse by the fact Lester kept squeezing the life out of his hitters until nothing was left for them but doubts.

“He did everything he had to do” Matheny said. “He kept us off balance and made pitches all night.”