Quentin Richardson added 14 points for the Knicks, the last NBA team to play a preseason game. They play again Saturday night at Philadelphia.
The Knicks went with what could be their starting lineup on opening night: Marbury and Steve Francis in the backcourt, Channing Frye and Jared Jeffries up front and Eddy Curry as the center.
The Nets were without stars Jason Kidd and Vince Carter, who were on the bench in street clothes. Carter hasn't played in either of New Jersey's games because of sore ribs.
With Kidd out, rookie Marcus Williams started at point guard and had 21 points and seven assists. Antoine Wright added 15 points and Richard Jefferson had 14. Jay Williams, trying to come back after not playing since 2003 following his motorcycle accident, was 0-for-3 with five turnovers in 16 minutes.
Thomas, the team president, was put in charge of coaching the team he assembled in June when Larry Brown was fired after compiling a 23-59 record in his only season in New York. Thomas has already been warned by Madison Square Garden chairman James Dolan that he'll be fired from both jobs if the Knicks don't improve this season.
He wants the Knicks to play a more up-tempo style, but there wasn't much tempo at all during a dreadfully slow first half in which the teams combined for 38 fouls and 55 free throw attempts.
The Knicks led 60-49 at halftime behind 12 points apiece from Marbury and Richardson and were comfortably ahead throughout the second half.
Renaldo Balkman -- whose pick was booed by New York fans on draft night when Thomas chose him at No. 20 instead of Williams -- had 11 points and seven rebounds in 16 energetic minutes.
Veteran swingman Jalen Rose did not dress, but the Knicks said he would start against the 76ers.