The time-honored saying is that no lead is considered safe at Fenway Park, and yet the Red Sox had to feel good about their chances on the afternoon of April 21, 2012, holding a commanding 9-0 lead over the rival Yankees through five innings.

A raucous crowd of 37,839 hardly blinked when Mark Teixeira cracked a sixth-inning solo homer, but the real fireworks were yet to come. The Bombers rallied for seven runs in the seventh inning and another seven in the eighth, posting a memorable 15-9 victory that can be seen Thursday at 6 p.m. ET on MLB’s Twitter, Facebook and YouTube channels.

“That was pretty cool,” Teixeira said at the time. “I've played in a lot of games, and that might have been the most fun regular-season game I've ever played in.”

Showtime’s Desus and Mero will be watching along and providing commentary and reactions to the game, which they have not seen before, with special guests expected to join during the broadcast.

Boston had built the early lead by hammering veteran Freddy Garcia for five runs on seven hits in 1 2/3 innings, then continued to pile on against relievers Clay Rapada and David Phelps. But when the Red Sox’s bats ran out of thump, the Yanks stirred against Boston’s beleaguered bullpen, following six solid innings by starter Felix Doubront.

In the seventh, Nick Swisher launched a grand slam off Vicente Padilla and Teixeira connected for his second homer of the game, a three-run shot off Matt Albers that drew New York within a run at 9-8.

Eduardo Nunez opened the eighth with a single off Franklin Morales, and Red Sox manager Bobby Valentine called upon former Yankee Alfredo Aceves, who walked Derek Jeter before Swisher put New York ahead with a two-run double to deep center field.

“That was the one that put us over the hump,” Swisher said at the time. “That’s a big win for us, man. That’s a huge momentum shift for us. This team, we never give up.”

Two more batters reached on walks (one intentionally) before Teixeira ripped a two-run ground-rule double off Aceves, extending the Yankees’ lead. Russell Martin later added a two-run double off Justin Thomas, and Jeter completed the scoring with an RBI single facing Junichi Tazawa.

“It was 9-0 after five innings and Tex hits the homer, and it seems kind of like an innocent homer at the time,” said Yankees manager Joe Girardi. “You’re able to put up back-to-back seven-run innings. I don’t think I’ve ever been a part of that at this level. This park, a lot of things can happen.”

The comeback cast a pall over Fenway’s 100th anniversary celebration, one day after the Yankees posted a 6-2 victory to open the weekend series. By the end, those Red Sox fans who remained were lustily booing the home squad -- including Valentine, who was just 14 games into his first and only season managing the club.

"It makes it a little more fun. There's no doubt," Teixeira said. "If you come back from nine runs against anybody, it's a cool thing. But to do it in Boston, it makes it a little more fun."