Red Sox second baseman Dustin Pedroia can’t contain his glee after tagging out the Blue Jays’ Lyle Overbay yesterday.

The Journal / Bob Breidenbach

BOSTON — One of the best parts of the season has arrived for Red Sox fans: Time to start counting down the magic number.

The Sox dropped the number they need to earn a postseason berth into single digits yesterday when they rode another outstanding pitching effort by Jon Lester and then hung on in an exciting finish for a 4-3 victory over Toronto at Fenway.

Later, Baltimore completed a 7-3 victory over Minnesota, reducing Boston’s magic number to eight. With 13 games left, the Sox have put themselves in great position to be playing in October once again.

If they play the way they did yesterday, they could make it another long October of baseball in Boston. While Lester once again excelled in winning his15th, the Sox did a little of everything in what was a playoff-like atmosphere going against 18-game winner Roy Halladay.

The Sox used some well executed small-ball, including a stolen base and a bunt, to score a couple early runs. They played excellent defense, especially late when the Blue Jays were rallying against Jonathan Papelbon. They took advantage of a couple Toronto mistakes to score insurance runs. And they got a bit of help from the umpires on a questionable call in the ninth that resulted in a huge out for Toronto.

“We played a good game,” is the way manager Terry Francona summed it up. “We did a lot of good things to put ourselves in a position where we win.”

“We played a really complete game today against a really tough pitcher,” agreed third baseman Mike Lowell, who scored a run and made several key defensive plays.

The biggest factor on a long list of positives was Lester. He went head-to-head with Halladay, one of the game’s best, and beat him.

“He was strong,” Francona said. “He had two-seam movement down, a cutter in, a couple changeups and threw a couple real good breaking balls. Boy, he was good and good thing. Halladay was pretty good, too. That was a nice matchup.”

Lester gave up a home run to Jose Bautista, the second batter he faced, then dominated. He went seven innings, allowing four hits, the one run, with two walks and six strikeouts.

“Any time you go up against Halladay or a pitcher like that, you just try to pitch your game and not worry about what he’s doing,” Lester said.

His team helped him when it came back in the bottom of the first and tied it. Jacoby Ellsbury singled, stole second, was sacrificed to third by Dustin Pedroia (how many times do you see the guy leading the league in hitting bunt a runner over in the first inning?) and then scored on Kevin Youkilis’ two-out single. Jason Bay doubled and scored on a bloop single by Coco Crisp to make it 2-1 in the second.

After that the two pitchers put on a show. Halladay, who was working on three days rest and who had pitched two complete games at Fenway this season, at one point retired 13 in a row. Lester set down nine in a row in the middle of the game.

When Toronto did threaten, the Sox made the plays behind Lester, most notably turning a double play in the seventh on a hard smash with two runners on by PC grad John McDonald. The Blue Jays, on the other hand, gave the Sox extra outs in the bottom of the seventh and Boston took advantage.

Lowell led off with a single to left. With one out, Jason Varitek hit a double-play ball to Lyle Overbay at first. Overbay booted it and both runners were safe. Alex Cora followed with another double-play grounder, this one to third.

Scott Rolen fielded it, but had to double pump waiting for Marco Scutaro to cover second. The delay gave Cora enough time to beat the relay to first and keep the inning alive. Crisp made the Jays pay with a bloop to left to score Lowell.

Boston added another run in the eighth when Alex Rios came in, failed to make a shoestring catch on a liner by David Ortiz and turned it into a triple. Ortiz scored on Youkilis’ sacrifice fly to center.

All the runs were needed. The Jays scored twice against Papelbon in the ninth and could have had more. Vernon Wells doubled and pinch-hitter Adam Lind singled to make it 4-2. Lyle Overbay hit a wall-ball to left. Bay played the carom nicely, whirled and fired to second. Pedroia made a quick tag. Umpire Doug Eddings called Overbay out, although replays indicated he got his hand on the base before the tag.

Rolen then hit a slow roller to third. Lowell charged, picked it up and fired on the run, barely getting Rolen on another close play. Toronto manager Cito Gaston was upset on the call against Overbay at second.

“The ball beat him there,” Gaston said, “and I think the umpire got blocked out. He said the ball beat him there, so most of the time, when the ball beats you, they’re going to call you out. . . You might have thought that he was out, but we’ve all seen that he wasn’t out. That was a big play for them that they got that call. Otherwise, we’re still out there playing.”

The end result is that the Sox won three of four in the series, Toronto is now all but dead in the playoff chase, and Boston begins a series tonight against the Rays with all kinds of playoff implications.

“Going into Tampa it’s going to be another pretty rowdy atmosphere,” Bay said. “It’s going to be fun. With the way we played this weekend, it’s definitely a good way to go into that.”

pkenyon@projo.com