The Wizards rallied from a six-point halftime deficit with a big third quarter and then came through down the stretch to successfully open a four-game road trip.
Miles Plumlee hit a hook shot with 2:43 to play that lifted the Suns into a 93-93 tie and Beal took over from there.
His 3-pointer came with 2:03 to go and put Washington in front for good. He added a jump shot with 27 seconds remaining to give the Wizards a four-point lead and finished things off with a rebound and dunk that accounted for the final score.
Goran Dragic led Phoenix with 19 points and 11 assists. The Suns had won their previous two games.
Notable deaths of 2014 [PHOTOS]