Jagr also moved past Steve Yzerman and into sole possession of eighth place on the NHL goals list, one behind Mark Messier. The 41-year-old Jagr's first power-play goal of the season was his team-leading 12th.
"It's an unbelievable feat, especially with the names on the list he's around and passing," Devils coach Pete DeBoer said. "It's an unbelievable accomplishment."
Boucher netted his first in the NHL and Stephen Gionta scored a short-handed goal during his first shift for the Devils (14-15-6) after an 11-game absence because of an ankle injury. Damien Brunner scored in the second and Eric Gelinas tallied in the third for New Jersey.
"He has instincts you can't teach," DeBoer said of Boucher. "I like a lot of things about him. He creates."
Jagr made it 3-0 at 2:08 of the second period on the power play. Andy Greene had the puck against the boards when he slipped it out to Travis Zajac, who quickly fed Jagr in front for a shot into the far side of the net.
Ottawa's players called a closed-door meeting after the game.
"Totally frustrated with our lack to string together another win," Ottawa captain Jason Spezza said. "We gave up a short-handed goal. Your power play is supposed to gain momentum for you. We gave up another pretty quick. It's tough to come back on the road, especially against a team like New Jersey."
Martin Brodeur won his 10th game of the season by making 23 saves against Ottawa (14-16-6).
Brunner scored a brilliant goal at 19:32 of the second to make it 4-1 for the Devils. The winger stripped Ottawa defenseman Jared Cowen of both the puck and his stick, then started left, deked right and came back left to slide the puck past Senators goalie Robin Lehner for his eighth goal.
"It might have looked like a slash, but he lets his stick go pretty easy," Brunner said. "I scored before like that, but not in the NHL. It's just instincts in front of the net, and I'm lucky it went in."
On the final play of the second period, Ottawa's Clarke MacArthur was assessed a double-minor for boarding and roughing, giving the Devils a four-minute power play to start the third. MacArthur tried to draw Anton Volchenkov into a fight, but he resisted, straight-arming MacArthur to keep him away.
The second period featured two sparkling saves by Brodeur, the first a glove save on a point-blank shot by Colin Greening and then another on a shot by Kyle Turris that he managed to cradle with his elbow and chest.
Gionta made an immediate impact upon his return, scoring his first goal of the season in his first shift in the opening period.
Volchenkov passed the puck to Adam Henrique for a 2-on-1 break. Henrique sent the puck to his right, where Gionta met it at the right circle for a shot that beat Lehner just 2:02 into the action.
Boucher drew cheers of "Bou-cher!" when he scored his first goal at 12:08 of the first period to make it 2-0. Gelinas, a fellow rookie, blasted a slap shot that bounced off the boards to the right of the net and rebounded in front, where Boucher scooped it in.
Ottawa got one back on a power play at 5:30 of the second when Greening redirected a slap shot by Erik Karlsson, which lifted up and over the shoulder of a screened Brodeur.
Milan Michalek scored for Ottawa at 8:35 of the third, but Gelinas responded when he put in a shot off a pass from behind by Brunner at 9:20.
Gionta scored the first short-handed goal for New Jersey in 23 games. Henrique scored the previous short-handed goal on Oct. 29 versus Tampa Bay. ... Gelinas picked up his 11th assist. He had come in tied for first in assists among NHL rookie defensemen. ... Michalek's power-play goal in the third period gave him eight goals in 15 games versus the Devils.
Copyright by STATS LLC and The Associated Press
NEWARK, NJ - DECEMBER 18: A New Jersey Devils fan donates toys during the annual Toys For Tots night in conjuction...