Ellington had career bests with seven 3-pointers and 25 points, leading the Grizzlies over the Heat 104-86 on Sunday for their fifth straight win and the best start in franchise history.
"I don't think Ellington will be able to sneak in the back door anymore," Miami center Chris Bosh said. "I didn't know he could shoot the ball like that. We know now."
The Grizzlies (5-1) snapped Miami's four-game winning streak while topping the 4-1 start in 2000-01 in this franchise's last season in Vancouver. They also extended their own team-record home winning streak to 14 dating to last season.
Rudy Gay added 21 points and Randolph had his sixth double-double with 18 points and 12 rebounds for Memphis. Mike Conley had 18 points and nine assists, while Gasol added 10 rebounds and six assists.
"We played outstanding basketball," Memphis coach Lionel Hollins said.
Bosh scored 22 points and LeBron James had 20 for Miami. Dwyane Wade came in averaging 20.4 points but was held to eight in his first game back after missing Friday night's win at Atlanta with a cold. Miami coach Erik Spoelstra said they expected teams to be coming after the Heat on this six-game road trip.
"There were critical places in where the game turned like sloppy turnovers, missed shots or big baskets that couldn't get us over that hump," Spoelstra said. "They played very well. They played physical, and they did what they needed to do to bring it home."
Memphis never trailed and the Heat managed to tie it only twice, the last at 14-all.
The Grizzlies had the biggest edge in this game beyond the arc, where they went 14 of 24 (58.3 percent), and at one point were shooting a better percentage from outside the arc than the Heat shot at the free throw line. Miami came in as the league's second-best team at the line, averaging 82.9 percent, but finished 22 of 36 (61.1 percent).
James said their game plan was protecting the paint.
"They are close to last in 3-pointers made and 3-pointers attempted per game," James said. "We paid for it today. They shot the ball extremely well."
The Grizzlies led 22-21 after the first quarter then Ellington scored 16 in the second to help Memphis outscore Miami 34-20 in the period. When Miami pulled to 42-40, Hollins took a timeout with 2:36 left. The Grizzlies responded with a 14-1 run for a 56-41 halftime lead.
This was a game Ellington thought he could have in the right situation after helping North Carolina win the 2009 NCAA national title. The Grizzlies traded Dante Cunningham to Minnesota on July 24, wanting to add Ellington's outside shooting to their bench.
"I think right here is a great situation for me where I got ... those guys down low, and they need a guy that can really knock down shots," said Ellington, who finished 8 of 13 from the floor and 7 of 11 beyond the arc.
Randolph called this "a statement game" for the Grizzlies. They visit Oklahoma City, the defending Western Conference champs, on Wednesday night before hosting the undefeated New York Knicks on Friday. When asked about the Grizzlies having the Thunder and Knicks, Gay had a quick answer.
"They have us," he said.
Miami had a 25-20 edge in the third quarter but never got closer than when Bosh hit a pull-up jumper with 6:45 left to pull the Heat to 63-58.
The Grizzlies had their chances to wilt against Miami in the fourth. Jerryd Bayless threw up a ball that never came close to the rim -- if it was even a shot attempt -- but Gay got a hand on it and tipped it to Randolph, who scored and converted on the three-point play for an 85-75 lead with 8:07 left.
Ray Allen tried to get the Heat going, running down court for a dunk only to be blocked by Bayless. Ellington capped the fast break going the other way with his sixth 3-pointer for an 88-76 lead with 7:20 left, bringing fans to their feet.
There was a time when the Heat came to town with enough fans in the stands to make the visit to Memphis feel almost like a home away from home. Not anymore as even Shane Battier, beloved for his time in Memphis, was booed during introductions with fans cheering as his first 3-point attempt went in and out.
This marked the seventh time in the Heat's Big Three era that they have allowed at least 14 3s in a game, and they now are 1-6 in those contests. ... It was the most 3s by the Grizzlies in the last 345 games, including playoffs. ... The Heat went 1 of 7 at the line in the first quarter, the NBA's worst free-throw shooting in that period since Golden State was 1 of 9 against Utah on Nov. 4, 2006, with a minimum of seven attempts. ... Ellington's previous career high had been 18 twice, last on Feb. 16, 2011 against the Clippers. ... The Grizzlies now are 4-0 when scoring at least 100 points this season. ... Memphis now has won three of four against Miami since James and Bosh joined the Heat in the summer of 2010.