This is why, for months, we hoped the Washington Wizards and Boston Celtics would settle their simmering feud in the postseason. All that regular season barking and shoving and mean-mugging, all the fingers to the face and the Wizards dressing in black before a game created potential for show-stopping playoff basketball. On Tuesday night, possibility exploded into captivating reality.

In Game 2 of the Eastern Conference semifinals, this best-of-seven matchup rose from a mellow first game and provided the thrills and strain to justify the anticipation. This was a bloody good game, literally, the perfect combination of brutal and appealing. It was painful to watch. It was beautiful to watch.

When 53 nerve-fraying minutes ended, the Celtics had claimed a 129-119 overtime victory at TD Garden. Once again, the Wizards flubbed a double-digit lead and a chance to steal a road win. But this felt more like a heads-up than a game of lasting significance. The message: The competition is on, and it’s hotter than anything these relatively young playoff squads have experienced. Let’s hope it doesn’t turn off until after the final second of Game 7.

“They’re a really good team,” said Celtics Coach Brad Stevens, who spoke with caution after Boston took a 2-0 series lead. “I don’t know if we figured anything out. We were lucky to win.”

We were lucky to witness one of the greatest point guard duels in NBA playoff history. Celtics star Isaiah Thomas, jawing with Wizards forward Markieff Morris for most of the night, scored 53 points, darting and bouncing off defenders, seemingly convincing shots to fall into the basket. On the other end, John Wall finished with 40 points and 13 assists, punishing Boston with speed and power.

The referees hold back Celtics guard Isaiah Thomas as the teams get chippy in the second half. (Jonathan Newton/The Washington Post)

[Isaiah Thomas outduels John Wall as Wizards let Game 2 slip away]

But at the end, Thomas’s clever offensive arsenal trumped Wall’s playmaking genius. Thomas scored 20 points in the fourth quarter, nine more in overtime, and he celebrated by pointing at his wrist to remind the adoring crowd of 18,624 that the clutch is his time.

He did this after undergoing about 10 hours of dental workthe past two days to repair damage from having a front tooth knocked out in Game 1. And he did this for his sister, Chyna, who was killed in a car accident last month. Thomas returned home to Tacoma, Wash., to attend her funeral last weekend. Tuesday would have been Chyna’s 23rd birthday.

“Everything I do is for her,” Thomas said during an on-court interview with TNT. “And she’s watching over me.”

Said Stevens of Thomas: “What else is there to say? You know, there’s a point today when he was not feeling good at all and was having a tough day, and I thought he was going to really have to gut this one out. And he not only guts it out, he ends up with 50. Pretty impressive.”

[Wizards-Celtics Game 2 best and worst]

Meanwhile, Wall’s magnificence faded late; he missed seven of his final nine shots and committed three turnovers in the fourth quarter and overtime. He missed a potential game-winning jumper in the closing seconds of regulation. Bradley Beal, who was just 4 for 15 from the field, chased down the rebound but air-balled a 15-footer as time expired.

Wizards guard John Wall grimaces and holds his left wrist after falling on the court during Game 2. (Jonathan Newton/The Washington Post)

Playoff defense has yet to arrive in this series, but Tuesday night did include some of the physical play, all-out effort and wince-inducing collisions that you expect. Wall fell on his left wrist after swooping in to try to challenge Kelly Olynyk on a drive to the basket. Avery Bradley injured his right hip while vying for a rebound. Otto Porter Jr. spent several minutes on the court after Jae Crowder clocked him under the basket. And while suffering through his toughest first half of the playoffs, Beal took a shot to the face and landed hard several times, the victim of a Celtics defense intent on limiting his effectiveness.

The first game was light sparring compared to this battle. Thomas had his face slammed onto the hardwood. Porter didn’t just experience the Crowder hard foul; in the third quarter, he was hit in the nose, and blood spewed. Of course, it got testy, which led to Morris and Thomas receiving double technical fouls for a third-quarter argument. But while the players grew frustrated, this was mostly a hard, clean basketball game. And it was played at the lightning pace that Wall and Thomas prefer.

[Markieff Morris has eventful game against Celtics despite bad ankle]

Despite the intensity, the all-star point guards made this an offensive game. From the start, Wall and Thomas staged a shootout. In the first quarter, Wall produced19 points and six assists and helped the Wizards to a 42-29 lead. Thomas had 15 points.

By halftime, Wall had 23 points and nine assists. Thomas scored 20. The Celtics shot 61.1 percent in the first half, and the Wizards were at 54.3. The teams combined to make 13 of 28 three-pointers. Games this physical used to be a harbinger of ugly, low-scoring affairs. But now, in a league of running and gunning, pacing and spacing, the elite point guards can make sure it won’t be an eyesore.

Before the series started, Wizards Coach Scott Brooks predicted the teams’ well-chronicled dislike of each other wouldn’t influence the quality of play.

“It’s not going to be ’90s basketball,” Brooks said. “Those days are done. They’re not coming back, and thank goodness they’re not because it’s a great game to watch. It’s free-flowing, and it’s pleasant on the eye. And it’s not football.”

[Scott Brooks finds Washington ‘magical.’ The feeling is becoming mutual.]

For a product of that bygone era, Brooks surprisingly resists nostalgia, and he doesn’t romanticize those days. He’s comfortable with how the game has evolved, and for good reason. This series is turning into a compelling example of what we should’ve learned the past few years: Postseason bruising is inevitable, but the game’s beauty doesn’t have to be optional.

In that aspect, the NBA is much closer to its 1980s heyday than purists would admit. No, today’s game is nowhere near as consistently physical because rule changes have softened the style, and even when the game turns rugged, it doesn’t reach the peak of past eras. But the game can again combine grace and grit without damaging the product.

As Wall and Thomas dueled, as TD Garden shook with energy, as bodies flew and blood spilled, this series became the fascinating showdown we anticipated. Even though the Celtics lead 2-0, don’t think this is over. This series has only begun to entertain.