A non-roster invitee to Spring Training, Green has ably filled a void created by the absence of the injured Jed Lowrie and the ineffectiveness of Julio Lugo. In a season that's already exceeded his expectations, Sunday's heroics symbolized just how far Green has come in a span of three months.
"He's been a big part of our team so far this year -- especially playing that shortstop spot, where there's been a lot made of it," Sox left fielder Jason Bay said. "For him to come through in the clutch right there, it couldn't happen to a better guy."
"It's gotten to a point where he's just been a really good player," Boston manager Terry Francona said. "Not a really good non-roster player, but a really good Major League player."
In an odd twist, Green's only other walk-off home run as a Major Leaguer came against the Red Sox -- as a member of the Braves. He took Boston's Anastacio Martinez deep in the 12th inning of a July 2, 2004, game at Turner Field.
"I hit that one better," Green said of his first walk-off blast. "It's fun anytime you can do something good for the team, especially at a point when we needed it. We wanted to finish it as soon as we could.
"At first, I didn't even realize what was going on. I didn't comprehend the fact that it was a walk-off. I realized it when I hit second base and everyone was standing at home plate -- then I realized what was going on."
Green's shining moment followed a solid effort from veteran Tim Wakefield, who allowed four runs on nine hits over 6 2/3 innings.
Atlanta (32-36) wasted little time executing its free-swinging approach against Wakefield. Following singles by Nate McLouth and Yunel Escobar to open the game, Brian McCann knocked in the pair with a double to right.
Boston (42-27) answered in the bottom of the inning, thanks in large part to a fielding gaffe by Atlanta starter Jair Jurrjens.
With one out, the right-hander misplayed a comebacker off the bat of Kevin Youkilis. Bay followed with a sacrifice fly to right, scoring Dustin Pedroia, and David Ortiz walloped a Jurrjens offering into the second row of the Monster Seats for a two-run shot.
George Kottaras' bases-loaded sacrifice fly in the fourth stretched Boston's lead to 4-2, but Atlanta responded in the seventh. Gregor Blanco and McLouth tied the game with back-to-back RBI singles off Wakefield and Ramon Ramirez, respectively.
Former Brave J.D. Drew put the Sox on top in the bottom half of the frame, plating Kottaras with a line-drive single to left off Eric O'Flaherty.
Atlanta refused to go quietly against the Boston bullpen, as Garret Anderson's RBI single in the eighth pulled the Braves even once again.
Jonathan Papelbon (1-1) worked out of a bases-loaded jam in the ninth, fanning Matt Diaz with a high 95-mph heater to end the threat.
The closer's escape act set the stage for Green, who drove the first pitch he saw from Atlanta's Jeff Bennett (2-4) through a rainy wind and inside Pesky's Pole.
"The last thing I wanted to do was hit the ball in the air, because the wind was so bad," Green said. "But I thought I hit it decent. Fortunately, the wind was blowing to the right. It blew the ball right where it needed to go."
John Barone is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.