Lopez, who finished with 25 points, started slowly but passed Williams with a turnaround jumper on the baseline with just over 4 minutes left. Williams' career spanned 17 seasons from 1981 to '98, the first eight of which were with the New Jersey Nets.
Lopez said he didn't take moving to the top of the Nets' record books with his 10,441st point lightly.
"It's a great honor, obviously a lot of amazing players have played here," Lopez said. "I'm just proud to have my name up there with those guys."
Information from The Associated Press was used in this report.