Struggling Washington upset injury-nagged NBA win leader Chicago 87-84 while the Miami Heat, also without a key star, rallied late behind LeBron James to defeat host New Jersey 101-98.
As a result, the Heat closed the gap on Chicago in the fight for the best overall record in the Eastern Conference and a home-court playoff advantage into the NBA Finals, Miami improving to 43-17 while the Bulls fell to 46-15.
The Heat play host to Chicago on Thursday in what figures to be a critical showdown to decide which of them will be the overall top seed in the East for the playoffs, which begin on April 28.
Chicago played without reigning NBA Most Valuable Player Derrick Rose, who missed his 24th game of the lockout-shortened season with a sore right foot, and Britain's Luol Deng, who has a right rib injury.
Miami was missing star guard Dwyane Wade, who was rested by the Heat, while the Nets lacked star Deron Williams, who was nursing an injured right calf.
At Chicago, a James Singleton dunk gave the Wizards an 82-77 lead with 1:40 remaining but C.J. Watson answered with a jumper for the Bulls. John Wall hit one free throw but Watson sank another jumper to pull Chicago within 83-81.
Two more Wall free throws with 22 seconds remaining gave Washington an 85-81 edge but Watson responded with a 3-pointer with 16 seconds to play to pull Chicago within 85-84 before the Wizards added two Maurice Evans free throws to produce the final margin.
Watson and Richard Hamilton missed 3-point shots in the final five seconds and the Wizards hung on for the upset victory, improving to 15-46, the NBA's second-worst record, with their first win in Chicago since 2008.
Hamilton led the Bulls with 22 points while Watson added 17 and Carlos Boozer contributed 16 points and 13 rebounds. Kevin Seraphin led Washington with 21 points and 13 rebounds.
At New Jersey, LeBron James scored eight of his game-high 37 points in the last 90 seconds to rally the Heat. Cris Bosh added 22 points and 15 rebounds.
The Nets led 96-93 before James scored eight points in a row down the stretch to seize a victory.
A James layup pulled Miami within 96-95 and another after a Gerald Green miss for the Nets put the Heat ahead to stay with 51 seconds remaining.
James hit an inside jumper with 13 seconds remaining for a 99-96 Miami lead and, after a Nets turnover, he hit two free throws to give Miami a five-point cushion.
MarShon Brooks hit a jumper for the Nets with .4 of a second remaining but it was too little and too late to keep New Jersey, already eliminated from playoff contention, from falling to 22-40.
Kris Humphries led New Jersey with 29 points while Brooks added 24.

LeBron James scored 29 points and grabbed 10 rebounds while Dwyane Wade added 28 points to power the Miami Heat over the New York Knicks 93-85 on Sunday in a possible first-round NBA playoff preview.
Chris Bosh added 16 points and a game-high 14 rebounds while James and Wade each contributed six assists and Wade grabbed nine rebounds as Miami improved to 42-17, second-best in the Eastern Conference and fourth overall in the NBA.
"We don't want to be playing our best right now. We want to continue to get better," Wade said. "We took a big step toward doing that tonight."
Carmelo Anthony scored 42 points and pulled down nine rebounds for the Knicks, who saw their nine-game home win streak come to an end.
At 31-29, the Knicks are eighth in the East, a half-game behind Philadelphia and two games in front of Milwaukee for the final East playoff berth.
Iman Shumpert's steal set up a Landry Fields layin that capped a 12-2 Knicks run and gave New York a 73-71 lead.
J.R. Smith slammed in a fast-break dunk to give the Knicks their largest lead at 79-75 only to have the Heat unleash an 18-3 run to seize an 93-82 lead. Wade scored 10 points for Miami in the decisive spurt.
"They turned up their defensive effort on us, caught us off guard, so we picked it up a little bit," Wade said. "We got the ball into the money guys' hands and we took care of business."
Anthony scored 14 points in the first quarter, a total of 22 in a first half where the Heat led by as much as 11 points but settled for a 46-44 advantage at half-time.
"Their bench came in and gave them a little roll in the second quarter," James said. "We stuck with what we were doing."