The foul overshadowed a solid performance from Adams, who chalked up 12 points and 10 rebounds (seven offensive) in the win.
It was another good start for the Thunder who looked for another win to gain ground on the fourth-placed Minnesota Timberwolves.
The side were able to win the opening two quarters to take a 54-40 lead into the half time break.
Washington aren't a side to be counted out, though, and came storming back into the match in the third quarter and outscored Oklahoma City 34-28 to draw closer.
The fourth quarter became a battle of the All-Stars, as Thunder point guard Russell Westbrook and Beal had an out and out scoring duel.
In the end, Westbrook (46 points) got the last laugh over Beal (41) with the Thunder closing out the win to stretch their winning streak to a league-high six games.
With the win, Oklahoma City move just one game behind the Timberwolves as they continue to hunt for a top-four playoff seed in the Western Conference.
And while they were opponents in this match, Westbrook and Beal, alongside fellow Wizards guard John Wall will team up in Team LeBron for the NBA All-Star game next month.
The All-Star teams were finalised on Friday, with captains LeBron James and Stephen Curry making their selections from the player pool.
Team LeBron will field James (Cleveland Cavaliers), Kyrie Irving (Boston Celtics), Kevin Durant (Golden State Warriors), and New Orleans Pelicans duo DeMarcus Cousins and Anthony Davis as their starting five. Westbrook, Beal and Wall will be joined on the bench by Kevin Love (Cavaliers), Victor Oladipo (Indiana Pacers), Kristaps Porzingis (New York Knicks) and LaMarcus Aldridge (San Antonio Spurs).
Team Curry will field Curry (Warriors), James Harden (Houston Rockets), DeMar DeRozan (Toronto Raptors), Giannis Antetokounmpo (Milwaukee Bucks) and Joel Embiid (Philadelphia 76ers). The bench will include Warriors duo Klay Thompson and Draymond Green, Minnesota duo Jimmy Butler and Karl-Anthony Towns, Damian Lillard (Portland Trailblazers), Al Horford (Celtics) and Kyle Lowry (Raptors).