Wideman finished his first career hat trick and sealed the win with a shot from the point with 1:19 left in the game.
Washington got even for its worst loss of the season with a good performance on the power play, which had been a weakness during the Capitals' recent woes.
Nicklas Backstrom also scored and had two assists for Washington.
Phil Kessel and Cody Franson scored for the Maple Leafs.
Jason Pominville scored at 2:19 of overtime, and Ryan Miller finished with 22 saves to lift Buffalo over Florida.
Derek Roy also scored for the Sabres (15-11-2), who won for just the third time in their past nine games (3-4-2). Buffalo also won for only the second time in its past eight home games.
Jason Garrison scored, and Scott Clemmensen finished with 18 saves for the Panthers (16-8-5), who failed to win their fourth straight for the first time since March 2008.
Pominville notched the winner with a wrist shot on a breakaway from the blue line.
Dustin Byfuglien scored 34 seconds into the first period and Winnipeg never looked back as it beat struggling Carolina.
Evander Kane, Tim Stapleton and Bryan Little also scored as the Jets (13-11-4) built a 4-0 lead after two periods and held on for their fourth straight win, their longest streak of the season. Blake Wheeler had three assists.
Justin Faulk scored his first goal of the season on a point shot that was redirected to get the Hurricanes (9-18-4) on the board, and Brandon Sutter added a power-play goal to make it 4-2.
Newly acquired defenseman Jaroslav Spacek, who came from Montreal in a Friday morning trade for Tomas Kaberle, assisted on both of Carolina's goals.
