A good victory and, paradoxically, the possibility of a good-sized loss.
Bynum was hurt when he came down on Lamar Odom's left foot after reaching back for a rebound with 8:52 left in the third quarter at Staples Center. He immediately grabbed his knee and moved very little as he lay on the court for several minutes.
X-rays at the arena were negative. An MRI exam will be done today, at which point Lakers officials are expected to provide a timetable for his return.
After Bynum went down, every player on the Lakers' bench went on the court and stood in a semicircle around him. He could not put weight on his left leg and was helped off the court by Ronny Turiaf and Kwame Brown. Fans chanted his last name as he left, but then an awkward silence, lasting several minutes, followed his departure.
Lakers officials were guarded with their comments, but Bynum spoke optimistically to reporters an hour later while leaning on crutches and wearing a large brace on the knee. He then walked down a long hallway without using the crutches.
"I think I'm fine because I can put weight on it and it doesn't hurt at all," Bynum said. "I can move it left and right. Just to take a step forward is the only thing that really hurts."
Bynum said the injury was "not as bad" as it initially looked.
"They put ice on it and it felt better right away," he said.
Coach Phil Jackson declined to speculate on a timetable for Bynum's return. Nor did he say he was necessarily worried.
"I'm not a person that starts fearing things," Jackson said. "We do know that Andrew's had a knee problem in the past when he was a kid. But I think it's not the problematic leg at all. It's the other one."
Bynum had 10 points and nine rebounds, and the Lakers (25-11) led at the time he was injured, 66-55.
The injury obviously means more time for Brown, the backup center who has averaged 5.3 points and 4.4 rebounds in eight games since returning from a 19-game layoff because of a sprained left knee and ankle.
Brown had three points on one-for-five shooting and six rebounds against the Grizzlies.
The Lakers were already thin at center without Chris Mihm, who is out one to two more weeks because of a sore right Achilles tendon. Turiaf will be the backup center until Bynum or Mihm returns.
The Lakers play tonight at Seattle (9-27), but a more challenging stretch awaits after that: Phoenix, Denver, San Antonio, Dallas and Cleveland.
With the Lakers ahead, 97-96, Bryant deflected a pass by Memphis guard Mike Miller and was fed downcourt by Brown for a fastbreak layup with 42 seconds left.
Rudy Gay, however, tied the score at 99-99 on a three-pointer from the corner with 32 seconds left.
Brown then missed a dunk on a feed from Luke Walton with 9.2 seconds left, but Gay fouled him on the play. Brown, a 40.7% free-throw shooter this season, hit the first attempt and was short on the second. Walton couldn't quite corral the rebound, and Memphis took possession with 7.5 seconds left.
Grizzlies guard Kyle Lowry missed a driving layup after some contact with Brown, Odom batted the ball out beyond the three-point line and Hakim Warrick missed a three-point attempt as time expired.
"I was pleasantly surprised," said Jackson, who tied Bill Fitch for fifth in NBA history with his 944th coaching victory. "I was all prepared for that game to go the other way because everything seemed to be happening the wrong way for us tonight."
Bryant, who missed Saturday's practice because of lingering effects of an upper-respiratory viral infection, sounded husky Sunday when he arrived 90 minutes before game time, saying, "I haven't eaten in a while."
He did not take part in the morning shoot-around at Staples Center. He did, however, make an unexpected appearance at a raffle after the shoot-around, which was attended by about 600 season-ticket holders as part of a credit-card promotion. Bryant even made an impromptu donation to the raffle after working out on his own for a few minutes.
"He took the shoes off his feet, signed them and walked to the locker room in his socks," said TV analyst Stu Lantz, who emceed the raffle. "It was not planned. The fans went nuts."
The opposite was true after Bynum went down several hours later.
The Lakers, and their fans, must now hold their breath and wait for MRI test results. The future of a promising season could hang in the balance.