What do Wilt Chamberlain, David Thompson, George Gervin and Vernon Maxwell have in common?

Very little, except the fact that they are the only players in NBA history to score 30 points or more in a quarter.Maxwell joined the elite group Saturday night, scoring 30 of his career-high 51 points in the fourth period as Houston rallied to beat Cleveland 103-97.

"I never really thought I'd score 50 points in an NBA game, much less 30 in a quarter," Maxwell said. "I played well and concentrated, especially in the fourth quarter. It wasn't a personal thing. Coach (Don) Chaney just called my plays."

Maxwell was 14 of 25 from the field, including 4 of 10 from 3-point range. He also made 19 of 22 free throws.

"He got incredibly hot because we let him catch the ball all the time," Cleveland coach Lenny Wilkens said. "But give him credit, he had one heck of a game and shot the ball extremely well."

Gervin holds the NBA record for most points in a quarter, scoring 33 for San Antonio on April 9, 1978. Thompson scored 32 in one period for Denver on the same day, while Chamberlain had 31 in the fourth quarter of his 100-point game on March 2, 1962.

"I've been around a long time, and that fourth quarter by Vernon was one of the most impressive displays I've seen," Chaney said.

The only other Rockets to score 50 or more points in a game are Elvin Hayes, Moses Malone, Calvin Murphy and Akeem Olajuwon. Murphy holds the club record with 57 against New Jersey in 1978.

Olajuwon is currently sidelined with an eye injury, so the other Rockets have to fill the gap left by their star center.

"In the next game, it may be somebody else," Maxwell said. "All I can say is this was my night."