Updated

By Steve Ginsburg

WASHINGTON (Reuters) - The Boston Celtics chalked up their ninth win a row and padded their Atlantic Division lead with a 104-102 victory over the Washington Wizards on Thursday.

Point guard Rajon Rondo had 21 points and 11 assists but the Celtics needed a foul shot by center Kendrick Perkins with five seconds left to take a 104-100 lead and put the game on ice.

With All Star Paul Pierce in foul trouble, Rondo and forward Kevin Garnett, who had 17 points on eight of 14 shooting, were the difference, said Celtics coach Doc Rivers.

"Rondo was great, especially down the stretch," he said. "The fouls threw Paul off his game a little bit. It was really the Rondo-Kevin pick-and-roll show.

"We got a lot of good stuff out of it. But one thing we need to do is go to lay-up practice. I don't know how many lay-ups we missed tonight but it was unbelievable."

Washington faced a 14-point halftime deficit but outscored the Celtics 22-6 to take a 72-70 lead. Boston countered with a 13-2 run to take an 83-74 lead into the final quarter.

"We came out with the 14-point lead and thought if we showed up in the third quarter that they would go away. And they didn't," said Rivers. "We didn't handle that well.

"I've said we're not a 48-minute team yet and that's great proof right there. But that's OK. We're still winning these games. We did it on the road and I'll take it."

DOMINATING LEAD

Boston (18-4) has a nine-game lead over the second-place Toronto Raptors in a division where the Celtics are the only team over .500. The Wizards (7-13) lost their third in a row.

Washington was paced in scoring by Gilbert Arenas's 19 points, but with the Wizards down 100-98 with 26 seconds left, the three-times All-Star guard missed two foul shots.

"Down two and we had our best player with the ball at the free throw line," said Wizards coach Flip Saunders. "Expected to make it, but didn't.

"We are doing things to put ourselves in position. Unfortunately, we haven't come up on the better end of the draw."

The Celtics won the championship two years ago but were unable to make a run at repeating because of injuries. Rivers said he thinks the team's confidence is building.

"We believe we can win games in any situation," he said. "That's a good sign. But we can't live on what we've done. The swagger is great as long as you back it up.

"In the third quarter we came out cool. We're not a cool team. We're a physical, tough basketball team. We do our jobs. When we don't do out jobs, we put ourselves in trouble."

(Editing by Peter Rutherford and Greg Stutchbury)