Mammoth 7-2 Islanders
Guenther (20) would score his first two goals in the second period, which helped give the Mammoth a 3-1 lead heading into the final frame.
After two power-play goals from his teammates, Mikhail Sergachev (6) and Clayton Keller (13), followed by a power-play goal from the Islanders' young phenom, Matthew Schaefer (10), Guenther found the net for a career day.
Nick Schmaltz (14) would score the final goal of the game to give the Mammoth the win as they improved to 19-19-1.
The Islanders fell to 22-15-4.
Senators 4-3 Capitals
Ottawa would edge by in a close one, thanks to a goal from Fabian Zetterlund (10) with just over two minutes left in regulation.
Washington originally got out to a 2-0 lead thanks to goals from Tom Wilson (22) and Dylan Strome (9), but the Senators responded with three straight goals of their own.
Aliaksei Protas (16) would tie it up for the Caps before Zetterlund would send home the eventual game-winner a couple of minutes later.
Ottawa improved to 19-15-5, breaking their three-game losing streak, while the Caps fell to 21-15-5
Ongoing
Carolina Hurricanes vs. Montreal Canadiens
Los Angeles Kings vs. Tampa Bay Lightning
Pittsburgh Penguins vs. Detroit Red Wings
Toronto Maple Leafs vs. Winnipeg Jets