NEW YORK -- Derrick Williams scored 19 points in another strong performance and the New York Knicks beat the Boston Celtics 101-95 on Friday night to remain unbeaten in the preseason.

The No. 2 overall pick of the 2011 draft who struggled in Minnesota and Sacramento just missed his third straight 20-point game and made a 3-pointer with 2:11 left after the Celtics had closed within two points.

Isaiah Thomas scored 13 in Boston's first preseason loss.

CELTICS: Jared Sullinger grabbed 10 rebounds but shot 1 of 8.

KNICKS: Kyle O'Quinn finished with 13 points and 11 rebounds.

INJURY UPDATES: Arron Afflalo started in his first action of the preseason for the Knicks after recovering from a sore left hamstring and scored eight points. ... Rookie Kristaps Porzingis sat out a second straight game with a strained left quadriceps but is expected to start Saturday at Charlotte.

WELCOME BACK: David Lee, who played for the Knicks from 2005-10, got a nice cheer when he was announced with Boston's starting lineup.

SEE YOU SOON: The Atlantic Division rivals meet again Thursday in Boston.

UP NEXT: The Celtics host Brooklyn on Monday. New York visits Charlotte on Saturday.