San Antonio superstar Wembanyama -- who had scored 35 points in the Spurs' game one win on Sunday -- exited in the second quarter at the Frost Bank Center in Texas after hitting his head on the court floor following a collision with Portland's Jrue Holiday.

The 22-year-old looked groggy as he lay on the floor for several minutes before getting to his feet and jogging to the locker room.

The 7ft 4in (2.24m) forward was subsequently ruled out of the remainder of the game after entering the concussion protocol.

San Antonio looked to have overcome Wembanyama's injury as they pulled into a 14-point lead early in the fourth quarter, leading 93-79 with just over eight minutes left on the clock.

But with victory seemingly in sight, San Antonio's shooting went ice cold and the absence of newly crowned NBA defensive player of the year Wembanyama was keenly felt as a determined Portland snaffled victory, closing the fourth quarter with a 27-10 run.

Scoot Henderson led Portland's scoring with 31 points, while Holiday added 16.

"Basketball is a game of runs, and the basketball gods are always gonna repay the ones that play the game right," Henderson told NBC television afterwards.

Game three of the best-of-seven series takes place in Portland on Friday.

- LeBron sparks Lakers -

Elsewhere Tuesday, the depleted Los Angeles Lakers produced another disciplined defensive effort to defeat the Houston Rockets 101-94 and take a surprise 2-0 lead in their Western Conference first round series.

With Luka Doncic and Austin Reaves injured in the final weeks of the regular season, many had all but written off the Lakers chances of mounting a serious challenge in the playoffs.

But LeBron James, Marcus Smart and Luke Kennard combined superbly to carry the Lakers to a second straight win over the Kevin Durant-led Rockets.

James finished with 28 points, while Smart added 25 and Kennard 23 to give the Lakers hope of advancing as the series heads to Houston for game three on Friday.

"As hard as we played in game one, we knew we had to double that in game two," James said.

"They were going to come in with desperation, so we had to be even more desperate. I thought we played a hell of a game.

"Our own mindset now is focused on game three," the 41-year-old NBA icon added.

"We know we're going into a hostile environment. Guys tend to play better at home than they do on the road so we have to be ready for that."

- Sixers bounce back -

In the Eastern Conference playoffs, Tyrese Maxey and VJ Edgecombe combined for 59 points as the Philadelphia 76ers scored a series-leveling 111-97 victory on the road over the Boston Celtics.

Edgecombe made six-of-10 three-point attempts before finishing with 30 points, 10 rebounds and two assists in a stunning victory for the Sixers, who had trailed 26-13 early in the first quarter before rallying.

Maxey was also lethal from long-range, making five three-pointers on his way to a 29-point haul.

The bounce-back victory came after the Sixers were thrashed 123-91 in game one on Sunday, after a performance that Philadelphia coach Nick Nurse lambasted as "absolutely unacceptable."

Nurse was unsurprisingly happier with his team's winning display on Tuesday.

"I thought we just played much better team defense tonight," said Nurse, who also saluted his team's resolve after Boston surged into an early double-digit lead.

"I think we did a great job of just taking that punch,” Nurse said.

Jaylen Brown led Boston's scoring with 36 points but Jayson Tatum was the only other Celtics player to make double figures with 19 points. The Celtics made just 35-of-89 shots from the field throughout the game.

Game three takes place in Philadelphia on Friday.