Whiteside had another big game with 25 points, 16 rebounds and four blocks, and Ellington scored 22 points off the bench, lifting the Heat over Denver 106-98 on Wednesday night.
Tyler Johnson returned after missing one game to get 18 points and seven assists for Miami. Goran Dragic had 16 points and seven assists for the Heat, who have more wins on the road (four) than at home (two).
"I like this group, I like the toughness that they're building," Heat coach Erik Spoelstra said. "Road wins are gratifying because they're tough. They're tough anywhere you go."
Nikola Jokic came off the bench with 17 points and 14 rebounds for Denver, which was outscored 31-18 in the fourth quarter to fall to 3-6 at home.
"We have to lock in for a full 48 minutes," Emmanuel Mudiay said. "I think sometimes we play the score instead of just playing hard every possession. That is somewhere we need to grow and get better at."
A thigh injury sidelined Ellington for the first 16 games of the season and he made his Heat debut in a home loss to Boston on Monday. He found his groove Wednesday and led Miami on a decisive 11-0 run early in the fourth to get the lead for good. Ellington hit four 3-pointers in the period, and his last put the Heat up 10 with 2:25 left.
"I got two open looks and I missed them," Ellington said. "I told Tyler next time he comes off, look at his shot first but watch me in the corner because sometimes (Wilson) Chandler's falling asleep. He did that and I knocked that one down. As a shooter and you knock one or two down in a row that's when you feel pretty good."
Jamal Murray's two 3-pointers got the Nuggets within five, but the Heat held on.
Whiteside had 25 points and 17 rebounds in the loss to Boston and has 15 double-doubles this season.
Chandler and Danilo Gallinari also scored 17 points each and combined for five of Denver's 19 turnovers.
"We talked pregame about we were taking care of the ball of late and we had 19 turnovers," coach Michael Malone said. "But more importantly gave up 28 points off those 19 turnovers."
Heat: G Dion Waiters was diagnosed with a torn muscle in his thigh. An MRI revealed a tear of the pectineus muscle, located in the front part of the upper and inner thigh. Spoelstra said Waiters, who stayed in Miami, will be re-evaluated in two weeks after rehab and treatment. ... Justise Winslow also remained in Miami to work on his conditioning. He has missed nine games with a sore left wrist. ... Josh Richardson tweaked his ankle in pregame and did not play. Spoelstra said the team will send him back to Miami for further evaluation.
Nuggets: G Will Barton missed his second game in a row due to soreness in his left ankle. Barton missed nine games after spraining the ankle, then returned for three before missing another for personal reasons. ... Darrell Arthur did not dress because of illness.
Johnson was reluctant to wear a mouth guard, but after getting an implant knocked out against Detroit last week and having oral surgery Monday, he understood the need to protect his teeth.
"I can't miss games because I'm missing teeth," he said. "My goal is to play all 82 and now I'm going to have to change it up and wear the mouthpiece."
The mouth guard didn't bother him in the first quarter when he had two dunks, including a slam at the quarter buzzer that pulled Miami within 30-28.
Heat: At Utah on Thursday night.
Nuggets: Host Houston on Friday night.