A 1-0 series deficit approached the Boston Celtics with near certainty when a forgotten man came to the forefront. Ray Allen would later put the finishing touches on Boston’s win, but Doc Rivers did not forget who had blazed the trail. This player had plugged Boston’s greatest weakness, had done so with enough conviction to provide hope even for his biggest detractors, had done so even under the storm of doubt that had surrounded him for months.

“We won the game because of Jermaine O’Neal,” Rivers said. Maybe that storm will dissipate now, at least slightly.

Everyone had counted out O’Neal, whose career had seemingly flat-lined some time in January, who had become the proverbial face on many Boston dartboards. But he did not react to his knee surgery with the same pessimism. Instead, a steely resolve was born, or at least developed, somewhere within him. Fans could give up on O’Neal. They could count him out, leave him for dead, piss on the grave they had buried him in. But he wasn’t ready to call it quits. Not with his first championship in sight.

When O’Neal’s season stood in purgatory, when doubts began to rise about whether he’d even return to the court this season, when the Celtics wondered whether his body would ever cooperate, the aging center called on Tim Grover. For three weeks, two times per day, without ever wanting to slow down, O’Neal worked with the world-renowned trainer. During his 15-year professional career, they were some of the most difficult workouts O’Neal had ever experienced. They were “at a different level,” he explained.

“All he did was show up, listen and work hard,” said Grover.

O’Neal’s first championship hung somewhere in the future, somewhere distant but perhaps within reach, and by then he probably knew how crucial to that championship he had become. Kendrick Perkins was gone, Shaq’s body was held together by silly putty, Nenad Krstic did not have the ideal spirit for a Celtics center, and Glen Davis struggled to play 30 solid minutes, never mind 48.  If the Celtics were to solidify themselves as contenders again, they needed a center they could count on. One who would be more Popeye than Olive Oyl. They needed the Jermaine O’Neal they thought they had signed last July, rather than the O’Neal whose body came unglued earlier this season.

As Paul Flannery noted, O’Neal’s breakout game was what the Celtics had planned for since day one. The O’Neal we saw last night—the one who blocked shots, altered others, drew crucial charges and shot six for six from the floor—was the player Boston thought it would get all season long. His season had gone full circle; from the potential difference in a Boston title run, to everybody’s favorite whipping boy, and back.

But back for how long? One grand slam did not make J.D. Drew a reliable clutch hitter. One hit song did not make Lil’ Flip a good rapper.  One out-of-this-world catch did not make David Tyree a trustworthy wide receiver. (Sorry, Patriots fans. If it makes you any better, I’m currently slamming my head against my table, too.) O’Neal needs to do this repeatedly. His body needs to hold up to the playoff grind. Even if it doesn’t, the Celtics will probably rely on him more than they should.

“At the end of the day, this is who we are. This is who we have,” Doc Rivers said of Boston’s center position. “And we’re fine. We’re ready.”

At least for one night, they were. And a glorious night it was. Beyond blocking some of Glen Davis’s shots, there wasn’t much else O’Neal could have done. With the Celtics down twelve points in the second half, he even somewhat took over the game on both ends. First he blocked Carmelo Anthony. Then he finished a little jumper in the lane. Then he blocked Carmelo again. Then, another jumper. There were offensive rebounds and putbacks, charges taken at the most opportune times, an undeniable presence that not only solidified Boston’s defense but also helped will the Celtics to victory. By the time Jermaine contributed his most timely help—taking a charge on Amare Stoudemire when the resulting Toney Douglas three, had it counted, would have pushed New York’s lead to seven points with just 2:15 left—people were swimming off the coast of Antarctica, snow was falling in Ecuador, and full-grown lions were being attacked by hamsters.

“The big thing with him is he’s healthy,” Kevin Garnett told WEEI. “His body feels good. He’s playing well. He has confidence in his body and what he’s doing. We’re feeling him. We’re looking for him. He’s a threat in our offense. I’m happy for him, man. I know he’s grinding and he’s been going through some difficult times with his leg and his body, so it’s good to see him out there.”

It’s good to see him out there, good to see him fulfilling the role Danny Ainge and many others envisioned back in July, good to see him recovered from his injury and helping the Celtics push toward the franchise’s 18th banner. That title, should it come, would be O’Neal’s first. Don’t think that’s lost on him.

“All these years, I’ve accomplished a lot of things in my career but it doesn’t really matter,” he said last week. “This is what matters. The champagne, the confetti, the tears—that’s what matters. I’m not about to let nothing—surgery, anything—take away at least the opportunity [to win a championship].”

After all he’s been through this season—the injuries, the doubts, the blanket of pessimism—that title, should it come, might even be sweeter than it is in his dreams.

“It’s been a rough year, no question,” O’Neal told CSNNE. “This is probably been the hardest year of my career just mentally. It’s just been a grind. My teammates, my brothers, have really helped me get through this. This city has helped me get through this. I just continue to work. It’s just one game. You’ve got to focus on some of the things you did good and try to get better the next game, that’s my thought process.”

It’s just one game. That’s true, and important to keep in mind. But there’s hope it could only be the beginning.