(Reuters) - The defending NBA champion Miami Heat blew away their second successive opponent in a 103-73 rout over Brooklyn on Wednesday.

The Heat, who have opened the new season with a revamped roster that has taken little time to mesh, followed up their 25-point victory over Phoenix on Monday with another impressive effort.

LeBron James sparkled with 20 points, 12 rebounds and eight assists while Dwyane Wade top scored with 22 points.

Miami (4-1) made 10 three-pointers and befuddled the Nets with their passing, breaking the game wide open in the third quarter.

Shane Battier and Mario Chalmers made back-to-back three-pointers to cap a 10-0 run that put the Heat up 64-46 in the third, and James closed the quarter with a three-pointer of his own that stretched the lead to 23.

"As long as the guys have the right mindset for this and the maturity that if we play our game and hit the open guy, then you can see the strength of our offense," Heat coach Erik Spoelstra told reporters.

Deron Williams scored 14 points for the Nets.

After making a big splash in the off-season by re-signing Williams along with Joe Johnson and relocating to Brooklyn, the Nets have yet to make their mark on the court.

"Nobody said we're on Miami's level. Nobody ever said it," said Brooklyn coach Avery Johnson.

"So we're not there yet. We're definitely not there after three games of the regular season."

The Nets were hurt by 19 turnovers which helped to feed the Miami offense.

The Heat also got strong performances from their newcomers with Rashard Lewis scoring 13 points on 6-of-9 shooting, while Ray Allen, having already won a game with a last second shot against Denver on Saturday, finished with nine points.

(Writing by Jahmal Corner in Los Angeles; Editing by Greg Stutchbury)