Alfredsson had three goals and four assists for an Ottawa-record seven points, leading the struggling Senators to an 8-4 victory over Tampa Bay on Thursday night.
"You could tell he was on fire," Senators goalie Martin Gerber said. "It was fun to watch, that's for sure."
Alfredsson and Jason Spezza, who had two goals and an assist, scored 29 seconds apart during Ottawa's three-goal first period. Alfredsson added a short-handed goal and his 500th career assist in the second as the Senators took a 5-0 lead.
"It's a lot of fun, especially the way the whole team played and the big win we needed today," Alfredsson said.
Tampa Bay's John Tortorella coached his 507th game, breaking a tie with Herb Brooks for most games coached by an American-born NHL coach.
Alfredsson topped his career high of six points at Buffalo on Nov. 2, 2005.
"Right now, the way I look at it, you add it up at the end of your career and you look back and maybe say, 'Oh, I remember that night in Tampa," Alfredsson said.
Tampa Bay defenseman Dan Boyle scored twice in his return to the lineup after missing the previous 36 games following left wrist surgery. Nick Tarnasky and Craig MacDonald had the Lightning's other goals.
"The wrist held up, and that's probably the only positive thing that came out of it," Boyle said. "It's been a frustrating year for me. A lot of stuff happened. There's going to be some pain and some weakness along the way, but nothing that's going to bother me down the road."
The Lightning, last in the Eastern Conference, had a three-game winning streak end. Tortorella's postgame media session was a short one, as he told reporters he wasn't going to answer questions.
"Every time we took one step, right away we took one back," Tampa Bay right wing Martin St. Louis said.
Alfredsson scored from the top of the left circle at 13:43 of the first. Spezza made it 2-0 from the high slot at 14:12.
Alfredsson scored a power-play goal with 1:19 left in the first and added his sixth short-handed goal of the season on a 2-on-1 to put Ottawa up 4-0 at 4:38 of the second.
"He's been as good as any player in the league from the playoffs until now," Senators coach John Paddock said. "I don't think anybody can argue with that."
Alfredsson got his 500th career assist on Vermette's goal later in the second at 9:36. Boyle cut the Tampa Bay deficit to 5-1 with 6:09 left in the period.
Both teams scored twice in the opening 5:07 of the third. Robitaille and McAmmond had the Ottawa goals, while Tarnasky and MacDonald scored for Tampa Bay.
Boyle scored his second of the game at 15:17 of the third. Spezza got the goal back with 3:27 remaining.
Alfredsson has scored 30 or more goals in four different seasons. ... Dallas co-general manager Brett Hull scouted his second Lightning home game in three days. Chicago and Phoenix also had a scout at the game. ... Ottawa RW Brian McGrattan (right shoulder) missed his second straight, and is listed as day to day. ... Senators D Wade Redden had his 300th career assist on Vermette's goal.