Chicago led 45-39 at halftime after shooting 39 percent. Deng led the Bulls with nine points. Seraphin had 10 points for the Wizards.
The Bulls opened the third quarter on an 11-4 run to take a 56-43 lead. The Wizards responded with a 15-4 spurt to pull within two with 3:35 left in the period. Chicago quickly pushed its advantage back to nine after a tip-in by Noah, a 3-pointer by Kirk Hinrich, and Belinelli's dunk.
Washington got back within three points early in the final quarter, but Chicago again had an answer. Nate Robinson made a layup, and Belinelli sank another 3-pointer to push the Bulls back in front by eight.
Thibodeau said Belinelli has gained confidence as the season has gone on.
"When you are new to a team, he was trying to fit in," Thibodeau said. "He was trying to learn the system. He has already proven to be a good player in this league, so it was a matter of time.
"Once he had a better understanding of his teammates, and they had a better understanding of him, he is good. He can score a lot of different ways."
The Wizards got off to a strong start, leading by as many as eight in the first quarter and taking a 26-22 lead at the end of the period.
Washington went cold in the second quarter, shooting 4 of 21.
Garrett Temple started at guard for the Wizards in place of Mack. Temple, signed by Washington on Tuesday, had 13 points Friday in a win over Orlando that snapped an eight-game losing streak.
Hamilton had nine points in 15 minutes Saturday. Thibodeau said he liked what he saw from Hamilton, especially when the veteran found a rhythm in the second half.
"We need his minutes. We need his shots. We need his points," Thibodeau said.
Belinelli replaced Hamilton with 4:38 left in the first quarter after Hamilton got off to a 2-for-5 start. Belinelli scored six points in the first half.
"In the first quarter, I tried to bring a little energy on defense and offense," Belinelli said. "Tonight was good."
NOTES: Washington is 1-13 on the road this season. ... The Wizards have lost 12 times in their past 15 trips to Chicago but they beat the Bulls 87-84 last April in their previous trip.