Sullinger actually heated up in the third, stringing together six straight points during a 10-0 run that handed the Celtics a 59-52 lead midway through the quarter.
Boston came out firing in the fourth, opening an early 11-point lead on the heels of two 3-pointers from Bayless, who also displayed his defensive skills when he hustled back on a break to block a wide-open layup by Ben McLemore with 7:45 to play.
"Just try and make plays. When you play well together, things work out," Bayless said. "It takes time for people to jell and right now you can see we are starting to jell a bit."
Bayless' block only sparked the Celtics — Sullinger in particular — further.
He followed the swat with a rebound and putback, delivered a three-point play, hit a 3 and added the fadeaway to help preserve the lead.
"Tip your hat to Jared Sullinger," Sacramento coach Michael Malone said. "He came out and dominated us tonight."
Rondo had played in eight games since missing nearly a year with a torn ACL, and the four-time All Star has been rounding into form, averaging 13.5 points, 10.5 assists, 7.5 rebounds and 2.5 steals in Boston's last two games.
Sacramento was missing one of its top threats as well. Rudy Gay, averaging 20.3 points and 6.2 rebounds per game, sat out with an illness.
NOTES: Boston C Vitor Faverani (knee) and Sacramento G Marcus Thornton (hip) also did not play. . Cousins was averaging 25 points and 13 rebounds over his last two games. He scored 13 points on 6-of-9 shooting in the first quarter Friday. . Sacramento lost its sixth straight in Boston. . Boston shot 45.5 percent (40 of 88) in the opening half, while Sacramento shot 35.6 percent (31 of 87). . Thomas and Bayless got into a scuffle with 5:11 remaining, and both players had to be separated by teammates and referees. . Bradley has missed six of the last eight games with a sprained right ankle.