The Knicks led 73-70 heading into the last period, but their hopes of a sixth successive win were hit by a John Wall-inspired Wizards outfit.
Wall, who top-scored for Washington with 21 points, helped his team take control while Trevor Ariza contributed 20 points.
There was no such upset in Miami, where the Heat improved their home record to 20 wins from 23 matches after seeing off the resilient Houston Rockets 114-108.
Star players LeBron James and Dwayne Wade were in sparkling form, pouring in 32 and 31 points respectively, the latter also contributing eight assists.
The San Antonio Spurs claimed their 11th consecutive win after beating the Minnesota Timberwolves 104-94.
Danny Green scored a career-high 28 points, including eight three-pointers, as the in-form team of the NBA stepped up a gear with the scores tied at 77-77 in the final quarter.
Roy Hibbert led the Indiana Pacers to a 88-69 win over the Philadelphia 76ers with 18 points and 14 rebounds as the Eastern Conference Central leaders extended their winning streak to five matches.
The Oklahoma City Thunder claimed back-to-back wins for the first time in nearly three weeks after sauntering past the Golden State Warriors 119-98.
Kevin Durant led the way with 25 points, while Russell Westbrook also stood out after adding 22.
The Los Angeles Clippers turned in a fantastic third period which was pivotal in their 86-76 win over the Orlando Magic, who stretched their winless run to 11 games.
Trailing by two points at half-time, the Clippers came out all guns blazing in the third quarter to take a nine-point lead into the final period and they avoided any late slip-ups against their beleaguered opponents.
Jeff Teague poured in 22 points as the Atlanta Hawks defeated the Memphis Grizzlies 103-92 and Brook Lopez's 17-point haul saw the Brooklyn Nets squeeze past Detroit 93-90 - their first victory over the Pistons in nearly seven years.
Dallas coach Rick Carlisle was given his 500th career victory after his Mavericks side overcame the Portland Trail Blazers 105-99, while Kevin Garnett's season-high 27 points inspired the Boston Celtics to a 99-95 success over the Toronto Raptors.
Kyrie Irving bagged 22 points as the Cleveland Cavaliers crushed the Charlotte Bobcats 122-95, the New Orleans Hornets got their first win in five after beating the Phoenix Suns 93-84 and Paul Millsap and Al Jefferson both poured in 19 points in the Utah Jazz's 100-86 win over the Milwaukee Bucks.