Pageau got his own rebound and tucked the puck past the outstretched left leg of Jack Campbell. The forward, who leads the Senators with seven goals and has four in his past three games, said he hasn't felt this confident offensively since junior hockey.
"I don't think my role has been really offensive since I've been in the NHL," Pageau said. "It doesn't matter. I take pride in a role, defensively, playing against good players. It's a good challenge every night, and that's my mindset. I want to defend, and if you defend well, it's going to create some chances offensively."
WATCH: [All Kings vs. Senators highlights]
Artem Anisimov and Anthony Duclair scored, and Anders Nilsson made 26 saves for the Senators (5-9-1), who won for the fourth time in seven games (4-3-0).
"I think we had a strong showing there for 60 minutes," Duclair said. "[Nilsson] helped us all game; he played a great game. We definitely wanted to go into overtime and get that extra point for him."
Tyler Toffoli and Dustin Brown scored, and Campbell made 30 saves for the Kings (5-10-1), who are 1-5-1 in their past seven games.
"This was a good opportunity for our team, tonight, to win a hockey game," Kings defenseman Drew Doughty said. "I think our first was OK, the second they were a little bit better and then at the beginning of the third they were better than us, so you've got to play a full 60 minutes to win hockey games in this league, and they played better for the majority of the game."