"We didn't have Eric, so we needed to find those 20 points somewhere," Hornets coach Monty Williams said. "Jarrett Jack played very well. He gave us a calming effect. ... He's our leader and we'll need him to play like that all year."
The Celtics are 0-3 for the first time since 2006-07, the season before they traded to bring Kevin Garnett and Ray Allen in to help Paul Pierce, who has yet to play this season because of a bruised right heel.
Before the game, Celtics coach Doc Rivers worried aloud that the Hornets would be a feisty opponent because of how many NBA analysts have written them off since Paul was traded to the Los Angeles Clippers.
"This team's going to play with a chip on its shoulder the entire year," Rivers said. "If I was a player and all I heard was, 'If you lose Chris Paul it's be the demise of the franchise,' that would make we want to prove a lot of people wrong, and watching them in preseason and watching them in the first game, they pretty much played with that chip."
Gordon was out because he bruised his right knee in a season-opening win at Phoenix in which he scored a team-high 20 points.
Jack did not play in the win over the Suns on Monday night because of a one-game suspension stemming from a drunken-driving arrest last season. His return helped a Hornets squad looking for a boost in Gordon's absence.
"We have a lot of guys on this team that are hungry," Jack said. "A lot of guys want to prove themselves -- a lot of capable guys. Guys who've been around this league."
Power forward Carl Landry pitched in with 20 points and 11 rebounds for the Hornets.
Allen led Boston with 15 points.
"Our defense was terrible. Offensively we didn't execute. We looked scattered out there on the floor," Allen said. "That's just us and how we didn't execute on both ends of the floor and we know better."
"Defensively, we've got to get the trust in each other. We've let too many people score in our paint in all three games that we've played so far," Allen continued. "We're being tested. ... Our backs are up against the wall so we've got to come out swinging."
Kaman, who had 10 points and five rebounds off the bench in his Hornets debut Monday, came back with 12 points, nine rebounds and three blocked shots against Boston.
"I'm learning about this team, learning about my teammates," Kaman said. "Everything for me is an adjustment right now and I'm just trying to play off everybody and do the best I can. We have a good core group of guys here who care about the game and care about our teammates."
Kaman backed up Emeka Okafor, who had 13 points, six rebounds and five blocks. Marco Belinelli, who started for Gordon at shooting guard, was 3 of 4 from 3-point range and also finished with 13 points. Five of Landry's rebounds came on the offensive end, helping the Hornets outscore the Celtics 21-11 in second-chance points.
Garnett had a difficult night in what was Boston's third road game in four nights to open this lockout-compressed season. One night after scoring 12 in a loss at Miami, he finished with eight points on 4-of-10 shooting.
The Celtics shot like a team with tired legs, hitting only 37 percent from the field (29-of-78). New Orleans, by contrast, appeared energized by a sellout crowd, shooting 45.6 percent and outrebounding Boston 48-37.
"I just thought we played tired," Rivers said. "We looked old tonight."
The Hornets also had a whopping 46-24 advantage in points in the paint.
"Their guards beat us off the dribble most of the night," Rivers said. "They lived in the paint."
New Orleans took the lead for good late in the first quarter and Belinelli's 3 ignited a 13-4 run to open the fourth. Landry's jumper capped the spurt, giving New Orleans an 85-67 lead with 6:25 to go.
Boston's largest lead was 9-2 before the Hornets stiffened defensively and raced into the lead with an 8-0 run ignited by Belinelli's 3 and capped by Jack's steal and fast-break layup.
The Hornets led by as many as 16 points before taking a 48-49 lead into halftime.
Attendance for the home opener was announced as an overflow 17,802. ... Celtics rookie Greg Stiemsma blocked six shots. ... Boston also was without F-C Chris Wilcox, who has a bruised right shoulder. ... The Celtics return to Boston for their home opener on Friday against Detroit.