Brooklyn, playing the second half of a back-to-back after losing to the Los Angeles Lakers 95-90 on Tuesday, looked sluggish and tired after taking an early 39-26 lead.
"When we saw that lead, we got a little greedy and started thinking we could do it by ourselves," Williams said. "A lot of what happened out there was my fault. We didn't (do) the little things that you need to do to win games."
The Nets shot 73.7 percent in the first quarter, but went 24 of 64 (37.5 percent) the rest of the way and lost their second straight following a five-game winning streak.
Wallace was given the night off because of the back-to-back games, but it didn't seem to bother the Nets early.
Lopez got Brooklyn off to a fast start, but went to the bench midway through the first quarter after picking up his second foul.
Even without their 7-footer, the Nets seemed fine.
They shot 73.7 percent in the opening 12 minutes, had nine assists and took a 30-18 lead on a spinning layup in the lane by Williams with 23.8 seconds left.
Brooklyn extended its lead to 13 in the second quarter before Golden State went on a 15-6 run to close the gap. Lee had six points while Harrison Barnes had four, including a reverse under the basket that helped pull the Warriors within 46-41 at the half.
Golden State kept chipping away at the deficit after the break and pulled even at 58-all before Thompson hit his stride.
"Our defense really had a low grade in the third quarter," Nets coach Avery Johnson said. "They ran it up our throats, and then offensively we couldn't get anything going."
Joe Johnson had 13 points and six assists for Brooklyn. Kris Humphries added 10 points and six rebounds.
Landry finished with 11 points and five rebounds for the Warriors, who snapped a three-game losing streak to the Nets.
Note: Golden State forward Brandon Rush revealed he has a torn MCL in his left knee, the same knee in which he suffered a season-ending torn ACL earlier this year. The MCL injury must heal before Rush can have ACL surgery, which means December at the earliest. ... The Warriors improved to 7-0 when outrebounding their opponents. ... Thompson's 23 points matched his season high.