Stephen Weiss had a goal and two helpers, while Jassen Cullimore, Richard Zednik, Michael Frolik and Jay Bouwmeester also scored for the Panthers, who had lost two of their three previous games. Craig Anderson made 32 saves to earn his 12th victory of the season.
Alexander Ovechkin scored his league-leading 46th goal, while Alexander Semin also scored for the Caps, who fell for only the third time in nine games. Jose Theodore allowed four goals on 17 shots in the first period before giving way to Michal Neuvirth, who stopped 14-of-16 shots the rest of the way.
Nicklas Backstrom extended his point streak to a current league-high 10 games, posting an assist on Ovechkin's goal late in the third period.
Semin gave the Capitals an early lead 1 1/2 minutes into the game, but the edge was short-lived. Four straight goals from the Panthers gave Florida a huge advantage after the first period.
Weiss tied the game at the 3:53 mark of the first on a power-play goal, and then McCabe's power-play wrister from the right circle just over three minutes later put the Panthers in front.
Bouwmeester made it a two-goal game on the power play, blasting a slap shot from the left circle through traffic at 14:19. Keith Ballard's cross-ice feed to Zednik led to a one-timer that put the Panthers ahead 4-1 with 3:44 left in the frame.
Theodore was pulled in favor of Neuvirth in the second period, but Cullimore added his second goal of the year at the 10:24 mark to give Florida a 5-1 lead after two periods. Anderson made five saves in the frame to keep Washington off the board.
Frolik notched the only goal of the third for the Panthers, as the visitors cruised to the easy win. Ovechkin's goal with 21.8 seconds left accounted for the final margin.
The season series is tied, 2-2...Florida is 2-2-0 on a current five-game road trip that wraps up Tuesday in Atlanta...Washington fell to 25-7-1 at home, while Florida improved to 15-15-3 on the road...The Capitals still lead the Panthers by 13 points in the Southeast Division.