The Miami Heat rallied to beat the Boston Celtics 106-98 and clinch an NBA playoff berth on Wednesday as the post-season picture began to get clearer.
Dallas also secured a playoff spot after Luka Doncic scored 35 points and handed out 13 assists to lead the Mavericks to a 120-112 victory over the Cleveland Cavaliers.
The Cavs' defeat meant either the Eastern Conference-leading Heat or Celtics would be sure of a berth, and it was a tense finish in Boston.
Jimmy Butler scored 24 points and Kyle Lowry added 23 as Miami came out on top in a game that featured 16 lead changes.
Bam Adebayo finished with 17 points and 12 rebounds for the Heat, who pushed a one-point halftime lead to as many as 11, but trailed 83-79 going into the final quarter.
Jaylen Brown scored 28 points and pulled down 10 rebounds, and Jayson Tatum added 23 points and six assists for Boston.
But the Celtics couldn't hold off Miami, who took a 102-96 lead on Butler's dunk with 1:43 remaining.
Tatum answered with a layup but on his next attempt was called for an offensive foul, and the Heat finally sealed it with a string of free throws.
"We really had to step up and make multiple efforts," Heat coach Erik Spoelstra said. "They just keep on attacking regardless of what your scheme is."
But Spoelstra said the tight finish was just what his team needed to prepare for the playoffs.
"That's why I like going through a lot of these type of games in the regular season," he said. "We had some big-time performances down the stretch."
The Mavs' playoff spot was assured with their win as well as the Toronto Raptors' 125-102 victory over the Minnesota Timberwolves.
Doncic scored 20 points in the third quarter, when Dallas out-scored Cleveland 39-22 to claw back from a six-point half-time deficit.
The Slovenian star received a rapturous welcome in Cleveland, which has a large Slovenian population, and finished one rebound shy of his second 30-point triple-double in as many nights.
"When all the people come to see you, you want to put on a show," Doncic said.
Dorian Finney-Smith added a career-high 28 points, including six three-pointers for the Mavericks, who are in the playoffs for a third straight year.
The Cavs were led by Caris LeVert's 32 points. But they were without rookie of the year contender Evan Mobley, who will miss at least three games with a sprained ankle.
Cleveland are seventh in the East, two games behind the Raptors and Chicago Bulls in the battle for the last direct entry into the playoffs.
Suns hold off Warriors
The seventh through 10th-placed teams will battle in a play-in tournament for the remaining two spots from each conference.
The Golden State Warriors missed a chance to punch their playoff ticket, falling 107-103 to the Western Conference top seeds Phoenix.
Devin Booker and Mikal Bridges scored 22 points apiece as the Suns matched a franchise record with their 62nd win of the season.
It was touch and go, however, with six lead changes in the fourth quarter alone before the Suns put it away.
"It's big," said Chris Paul, who contributed 15 points and eight assists.
"Games like this can help you in the post-season, it makes you trust."
Jordan Poole scored 38 points to lead the Warriors as star Stephen Curry missed a seventh game with a sprained foot.
The Memphis Grizzlies locked up the second seed in the West behind Phoenix with a 112-111 victory over the Spurs in San Antonio.
Tyus Jones scored 25 points for the Grizzlies, who won the Southwest Division title for the first time in franchise history despite the fact that star Ja Morant missed his sixth straight game with a right knee injury.
The defeat dropped the Spurs a half-game behind the reeling Los Angeles Lakers for 10th in the West and the last berth in the play-in tournament.