Cancer didn't defeat the 23-year-old, and now it was time to see if he could help the Red Sox beat the Cleveland Indians.
Lester, a former Augusta GreenJacket whose rookie season ended prematurely when he was diagnosed with a treatable form of lymphoma nearly one year ago, returned to the mound on Monday to pitch the opener of a four-game series at Jacobs Field.
At a time when sports headlines were dominated by an NBA betting scandal, Michael Vick's alleged dogfighting involvement and an ongoing steroid investigation that has tainted Barry Bonds' chase of Henry Aaron's home run record, along came Lester.
"Wow, it's a great story," knuckleballer Tim Wakefield said, glancing in the direction of Lester's locker. "It's been a long road for him, but today's a day where you can say he made it back."
Lester's comeback from anaplastic large cell lymphoma - a cancer in the body's lymph system - has inspired the Red Sox, who were marveling at his composure and maturity long before he began chemotherapy treatments.
Lester was 7-2 with a 4.76 ERA last season when cancer cut short the left-hander's season, imperiling his young life. But by December, he was throwing again and the former second-round pick arrived at training camp in Florida in early February, two weeks before pitchers and catchers were due.
Although he appeared to be ready to pitch again in the majors, the Red Sox decided to bring Lester along slowly, allowing him to pitch in the minor leagues for more than three months before recalling him Monday from Triple-A Pawtucket.
Lester's return figured to be an emotional one for his family, Red Sox Nation and beyond.
"This isn't even about baseball," Curt Schilling said. "It just doesn't get any better the way a guy like that comes back to us. It's about family and we are all very excited. The big thing is he's a great human being and that makes it an even better story. That wasn't your run-of-the-mill DL stint."
Lester, who is from Tacoma, Wash., underwent six chemotherapy sessions before doctors deemed him free of a rare form of non-Hodgkin's lymphoma that was diagnosed a little more than one week after he beat the Los Angeles Angels on Aug. 23.
Red Sox manager Terry Francona did not have any pitch limits on Lester, whose parents were at Jacobs Field for his comeback.
"I ran into his mom and dad today at the mall," Francona said. "I'm sure they have some unbelievable feelings and I don't know what they are. But I bet you it's very emotional. Other than that, I think Jon wants to win."
Knowing him the way they do, his teammates said Lester wants to be known as a successful major league pitcher - not just a cancer survivor.
"I think everyone in this room would want it the same way," said Wakefield, who along with Mike Timlin took Lester hunting during spring training in Florida. "He's somebody who survived cancer but he doesn't want that label.
"He's not the type of person that would want your sympathy. He wants to prove himself and show that he can compete at this level."
Wakefield said Lester never spoke much about his illness, preferring to move on with his life.
"He's a great kid," Wakefield said, "very respectful and hard working. He's very quiet and very intelligent. He gets it. He handled it all as well as anyone you can imagine. You would never think he was 23."
Indians manager Eric Wedge was having trouble not pulling for Lester.
"You root for the guy in life," he said. "You hope that he has a long and healthy life. But we have to go out and compete against him, too. Other than that, I root for him in life."
Francona, a father of four, spoke with pride when asked about Lester's journey back.
"We thought he was a pretty special man before this transpired," he said, "and then he went through what he did with such grace that he's tough not to root for."