Terry Francona actually informed the left-hander he had the job in a text months ago. He was just told to keep it to himself until the manager finally went public before Lester pitched in a Grapefruit League game against the Braves on Wednesday.
"It was short and sweet," Lester said of the original notification. "I think I was in a deer stand."
Lester, 27, had a 19-9 record with a 3.25 ERA and 225 strikeouts in 208 innings last year. That's definitely the work of a staff ace.
"I think he deserves it," Francona said. "I think he kinda has that station in the game now where other teams probably look at him as No. 1."
Still, Francona played it coy for a while until making it official that Lester was his choice to start the opener.
"I don't know the exact day, but I know I gave him a holler during the winter and said, 'Hey, do you want to do this?'" recalled Francona. "He said, yeah, so I said 'OK, don't tell anybody.'"
"I don't think that's probably any surprise," Francona said in finally making the announcement.
"Obviously, it's a big honor," Lester said. "Growing up, it's kinda what you want to be."
Lester wasn't as sharp against the Braves as he had been in his first two Grapefruit League starts, when he didn't allow a run over six innings and struck out six.
This time Lester allowed eight hits and three earned runs in 4 2/3 innings. He tired in the fifth inning and gave up two runs after retiring 10 of 11 batters following three straight hits to start the game. He struck out four and walked two.
"The first inning was a little rough. I left some balls up," Lester said. "I made the adjustment the second through fourth innings. Then it got away from me a little in the fifth."
Overall, he called his outing "OK" and admitted getting ready for that Opening Day game was "still a work in progress."
"One more start and I'll be ready to go," Lester said.
Lester will face C.J. Wilson, who in February was named the Rangers' Opening Day starter. It will be Wilson's first opening start as well.
Josh Beckett started the past two openers for the Red Sox, but was just 6-6 with a 5.78 ERA as he battled back issues last season. He's been healthy this spring, but early on said that Lester deserved to get the opening start.
Lester has a 61-25 career record and 3.55 ERA. He was 16-6 in 2008 and 15-8 in 2009.
"It's a big honor and I understand it," Francona said. "But after that, it just kinda falls into place."
"Actually," the manager said, "I'm just about as excited about who to put out there two, three and four."
"Any of us could start on Opening Day," Lester said.
A second-inning single by Ryan Kalish accounted for Boston's only other base runner against Hanson. The right-hander struck out five, including the last three batters he faced to end a stretch of 10 straight outs.
The Red Sox scored twice in the seventh inning to tie the game and keep Lester from the loss. But the Braves scored on a bunt in the bottom of the inning to improve to 12-6 this spring. The Red Sox are 11-9 in the Grapefruit League.
First baseman Adrian Gonzalez, who made his Grapefruit League debut on Saturday after offseason shoulder surgery, played in his third game for the Red Sox and was 0-for-3.
Guy Curtright of the Atlanta Journal Constitution is a contributor to ESPNBoston.com. Information from The Associated Press was used in this report.