Miami has won five in a row, 16 of 18 and 11 straight at home, and has passed the Indiana Pacers for the best record in the Eastern Conference.
"When your team becomes confident and is recognized as one of the top teams in the league, you have to keep that going," Heat coach Pat Riley said. "We have established that."
P.J. Brown added 18 points in 26 minutes on 6-of-7 shooting as Miami shot a season-high 54.2 percent on 32-of-59 shooting.
"We're on the verge of becoming one of the elite teams," Mourning said. "We're getting there, but we won't be satisfied until we get to the finals."
Howard's eight straight points spanning the third and fourth quarters helped Washington cut a 20-point deficit to 73-67. The Wizards closed to 82-77 with 5:05 left on Jeff McInnis' second straight foul-line jumper.
Hardaway then made one of two free throws and followed a Wizards miss with a floater in the lane to boost Miami's lead to 85-77 with 4:04 left.
Richmond's 3-pointer with 1:50 remaining ended a 3:15 scoring drought for Washington and cut Miami's lead to 88-80.
Ben Wallace dunked to make it 88-82, but Hardaway delivered an off-balance fallaway jumper for a 90-82 advantage with under a minute left.
"We tried to come back from being down 20, but it was too long of a climb," Richmond said.
"It's routine for him," Dan Majerle said of Hardaway's late-game heroics. "When the game is on the line, he usually hits them."
Richmond scored nine points and Howard six as the Wizards closed the third quarter with an 18-8 run to trail 73-63 entering the fourth quarter.
"What I'm pleased about is that you get down 20 points here in Miami, as well as they're playing, and you (might) surrender," Wizards coach Bernie Bickerstaff said. "I thought the guys hung in there and got themselves in striking distance."
Miami led 49-38 at the half thanks to a late flurry of six points from Mourning and a 3-pointer by Hardaway. Brown scored eight points in the first quarter and 12 by halftime on 5-of-5 shooting.
- Dan Majerle's 3-pointer in the first quarter extended Miami's NBA record to 397 consecutive games with at least a trey.
- The Wizards' 38 first-half points Tuesday was a season low. Their previous low was 40.
- In the last six games, Washington is 2-4 without the injured Rod Strickland.
- If Miami defeats Indiana Saturday, it would tie a franchise record with its 12th straight win at home. Miami won 12 straight at the Arena from Feb. 15 to March 26, 1993.
© 1999 SportsLine USA, Inc. All rights reserved