Jon Lester’s performance was unremarkable. Jon Lester’s power was unbelievable.

There is no question that 2008 has been a revelation for the 24-year-old. Though he struggled with his command yesterday, Lester allowed one run in five innings in yesterday’s 14-2 win over the Orioles. He now owns a 13-5 record and 3.37 ERA. He has been among the top handful of starters in the American League this year.

Yet even that development may be less impressive than what Lester exhibited last night. At a time of year when pitchers should be wearing down, he seems almost impossibly strong.

Facing Baltimore leadoff hitter Brian Roberts in the first inning of last night’s game, Lester touched 97 mph on the Fenway Park radar gun. The development caused many to rub their eyes, wondering if Ken Kesey had been handing out Kool-Aid prior to the game.

But this was no illusion. Two pitches later, Lester did it again. A steady drumbeat followed, a consistent onslaught of 96 and 95 and 97 that Lester—pre- or post-cancer—had rarely if ever exhibited in his life.

“I think coming into this year the highest I'd ever thrown was 96 and that was a couple of years ago,” Lester said, recalling his exceptional 2005 campaign with Double-A Portland. “But it was one of those nights where I felt real strong, almost too strong.”

The velocity came at the expense of command, as Lester walked five batters, his most since April 14. Yet the Sox will gladly withstand a night of difficulties finding the strike zone in exchange for such compelling evidence of their pitcher’s strength in the final month of the regular season.

It seemed fair, after all, to wonder whether Lester might wear down as the calendar turned to September. He has now thrown 181.2 innings this year, destroying his previous professional high of 163 frames (a figure that includes the regular season and postseason in both the majors and minors), accomplished last year.

Lester has never before pitched a full six-month regular season without interruption. He has no business pitching without signs of fatigue. And yet…

“I can’t believe I’m saying this, but it’s September 2nd and it’s almost as if he’s too strong,” said Sox manager Terry Francona. “His stuff was phenomenal, the ball’s coming out of his hand, I think he touched 97 early in the game. He’s strong.”

How to explain the phenomenon? Aside from the obvious answer—a healthy offseason that he could devote to strength and conditioning, and a season in which he could maintain that program—there is the matter of Lester’s efficiency.

Last night’s 99-pitch, five-inning outing notwithstanding, Lester has become a far more economical pitcher this year than in seasons past. Though his innings load has jumped, he is throwing fewer pitches per inning.

This year, he is throwing 15.95 times in the average frame, down roughly 11 percent from the 17.94 pitches per inning that he required in his previous two big- league campaigns. He has gone from one of the least efficient pitchers in the majors to middle-of-the-pack (51st of 111 pitchers with at least 120 innings).

Moreover, an improved feel for his craft has allowed Lester to save bullets between starts. A pitcher who needed lengthy bullpen sessions as he searched for consistency in 2006 and 2007 no longer requires effort to maintain peak form.

“With Jon, who is seemingly getting stronger as the year progresses, we’ve curtailed his bullpens to probably 60 percent less volume than it was in April and May,” said Sox pitching coach John Farrell. “Part of that is how consistent he’s been. He’s very confident in the fact that, as long as I touch it up on the mound on day two or day three, he feels like he’s very well prepared mentally for his next start.”

The Sox have had little cause to argue the point. To the contrary, they are simply happy to embrace the fact that their de facto ace shows no signs of relenting.

In his previous start against the Yankees, Lester had delivered 6.2 brilliant innings, striking out eight and walking none while allowing one run. Yesterday, he again locked up an opposing offense, albeit a less formidable one. With as many as five starts left in the regular season, Lester shows every sign of being ready to answer the bell.

“In between starts I don’t feel this strong. You wake up the day you pitch and your body tells you it’s ready to go,” he said. “I feel good, which is fortunate. It’s a long season, a lot of innings. Right now I feel pretty good and hopefully I can just keep riding that way.”

Alex Speier is a Senior Writer for WEEI.com.