"Once you get that little confidence, that little swagger back you feel comfortable every night," Stone said. "I’m coming into games expecting to score."
Zack Smith, Shane Prince and Jean-Gabriel Pageau also scored for Ottawa, and Craig Anderson made 31 saves. Pageau added two assists.
The Senators gave the Lightning their second loss in 12 games.
Tampa Bay coach Jon Cooper didn’t make any excuses for his team’s lackluster performance.
"We’ve been on a pretty good run here of the last month and a half, two months and it came to a crashing halt," he said.
The Senators won back-to-back games for the first time since Jan. 18. They have been dealing with a fragile confidence of late, and coach Dave Cameron wants the team to build off these two wins.
"We’ve been in this position before where we’ve played pretty good in back-to-back games, we’ve done it before, but now you’re at the point in your schedule and in the season where there’s no margin for error here," Cameron said. "We have to get on a roll so this is a great way to start it and it starts with confidence."
Andrei Vasilevskiy stopped 24 of 28 shots for Tampa Bay. J.T. Brown scored the Lightning’s only goal.
For the second straight game, the Senators scored first and didn’t let up, giving the 17,078 on hand at Canadian Tire Centre something to cheer about.
"This is what we need," Stone said. "We’ve only been giving up very limited chances in our net and when Anderson only sees that many shots he’s not going to let in those four, five goals. … When you’ve got a world-class goalie and you’re only giving up a few chances against you’re giving yourself a chance to win every night."
Smith got his second goal in two games by opening the scoring at the five-minute mark. Stone dropped a pass back to him, and he beat Vasilevskiy top corner.
Prince made it 2-0 late in the period with his first since Nov. 25, but the Lightning cut the lead in half 34 seconds later when Brown took advantage of a rebound and beat Anderson from in close.
Ottawa padded the lead early in the second on Stone’s power-play goal, and midway through the period, Stone made it 4-1 after beating Vasilevskiy shortside.
Tampa Bay’s best chance to respond came late in the second when Nikita Kucherov broke in, but Anderson easily made the save.
Lightning coach Jon Cooper pulled Vasilevskiy at 11:24 of the third in favor of the extra attacker, but the move backfired when Pageau scored on the empty net.
With the Lightning back in action Tuesday night against Montreal, Cooper said things will need to be rectified immediately.
"This has to be a page turner because now we’ve got Montreal who’s won a couple and feeling good about themselves and we’re not," Cooper said.
"You’re not always encouraged about playing back-to-back, but I’m glad we get to jump right back at it (Tuesday) night."
NOTES: Ottawa D Jared Cowen and LW Nick Paul, as well as Tampa C Jonathan Marchessault and D Matthew Carle were healthy scratches. … The Senators are back in action Wednesday night against the Detroit Red Wings.