The Washington Wizards forced game seven against the Boston Celtics in the Eastern Conference semi-finals with a thrilling 92-91 win on Friday.

John Wall's go-ahead three-pointer with just 3.5 seconds remaining at Verizon Center saw the Wizards level the series at 3-3.

Isaiah Thomas missed a tough shot on the buzzer for the Celtics, who will host the series decider on Monday.

Along with Wall (26 points), Bradley Beal (33) and Markieff Morris (16 points and 11 rebounds) were instrumental for Washington.

Thomas and Avery Bradley each had 27 points for the Celtics, while Al Horford had 20 points and six rebounds.

Horford had put Boston 91-89 ahead with seven seconds remaining, but Wall responded.

Thomas was eight-of-24 from the field as the Celtics shot at just 40.5 per cent, slightly worse than Washington (43).

The winners of game seven will face the Cleveland Cavaliers in the Eastern Conference Finals.