In a mysterious and confusing scenario with a four-team tie in the Eastern Conference standings, the Celtics basically created the playoff matchup they desire least with their stunning second-half comeback against the Miami Heat on Wednesday night.

If the Celtics had lost — and they trailed by 24 at halftime — they would have dropped to the sixth seed and created a rematch with the No. 3 Heat, perhaps better than playing the Hawks or Hornets.

Instead, Celtics pride took over. Legends from the 1966, ’76, and ’86 title teams were in the house, and they participated in a halftime tribute. With Bill Russell watching intently, Bill Walton sitting next to buddy Kevin McHale, and Patriots coach Bill Belichick chomping on popcorn, the Celtics responded with a 60-26 run for a 98-88 win.

Now the Celtics will play the Hawks, who just thumped Boston, 118-107, last Saturday at Philips Arena and are 3-1 against the Green this season. It is the most uncomfortable opponent for the Celtics. The Hawks do Celtics things better than the Celtics.

Yet this was one of the Celtics’ more important victories of the season, especially after they produced their worst half of the season. Coming off yielding a 31-3 run on Monday against Charlotte — in a loss that cost them the No. 3 third seed — the Celtics trailed, 62-36, in the final minute of the first half with a Fan Appreciation Night crowd booing them steadily.

After the halftime tribute, the home team decided to recapture the defensive prowess and passion that had fueled them through their first 80 games. They outscored the Heat, 25-5, in the third quarter.

The Heat hit 28 shots in the first half. They hit two in the third quarter.

The crowd was ignited. And the Celtics transformed into the swarming defense with players making plays on instinct, avoiding the tension that had plagued them over the past week. The Boston team that some predicted would be a sleeper in the Eastern Conference playoffs, a potential conference finalist, had returned.

“I’d say it was one of the very few games that I’ve coached in where I wasn’t really paying attention to the score once that third quarter started, I was just paying attention to us,’’ Celtics coach Brad Stevens said. “And I was just enjoying watching us play. I knew, I thought maybe we’d run out of steam after that huge comeback, and sometimes that’s when you give it back, but our bench came in and kept it at the level that our starters started it and that’s why those comebacks are so unusual. But I was just enjoying watching us play, which was a nice change from the previous three quarters.’’

It was enjoyable for the home faithful, who understandably looked bewildered after watching the Celtics play six horrible quarters — all four against Charlotte and the first two on Wednesday. The Celtics looked unsure of themselves, even dating back to the final 18 minutes against the Hawks on Saturday.

For the first 79 games the season, the Celtics were a consistent bunch. They avoided long losing skids. They regularly played hard. Isaiah Thomas was stellar offensively. Jae Crowder was rugged defensively. The bench was dependable.

That somehow went awry over the past week, beginning when they owned an 87-75 lead at Atlanta with six minutes left in the third quarter, and were outscored, 43-20, the rest of the way. Before then, the Celtics had generally avoided the big runs because they were precise defensively.

That precision was prevalent in the second half Wednesday when Miami scored 26 points on 26.3 percent shooting with eight turnovers — including two shot-clock violations. The Celtics challenged every shot, stopped being so insecure, and trusted their help defense.

Victory became more important than a playoff opponent. Momentum is critical during this time of the season, and a loss — which would have been their third straight — could have sent the team into a malaise that could have lasted into the postseason.

At least they enter the Atlanta series with confidence, and now Stevens gets three days to plan for a formidable opponent. Boston is not filled with playoff veterans like those Big Three teams that could stumble into the postseason, get a couple of good nights’ sleep, and then turn into a juggernaut.

The Celtics were swept by Cleveland last season. Crowder, Thomas, Marcus Smart, and Kelly Olynyk have never won a playoff game, and then you’re asking them to turn it up after losing three consecutive games? That’s asking too much. They needed a win.

“That gives us some momentum, that gives us some confidence knowing what we’re capable of doing,’’ Thomas said. “We have to play with that intensity every game, every minute of each game, especially come playoff time. We’re confident in ourselves that we can win a playoff series.

“We’re ready to show the world what we’re capable of doing.’’

Gary Washburn can be reached at gwashburn@globe.com. Follow him on Twitter @GwashburnGlobe.