Boston Celtics' Ray Allen passes the ball up court as Miami Heat's Dwyane Wade looks on during the third quarter of Game 1 of their NBA Eastern Conference basketball playoff series in Miami May 1, 2011. (Xinhua/Reuters Photo)

Dwayne Wade and Miami sent a strong message to their Eastern Conference tormenters the Boston Celtics with a 99-90 victory on Sunday that gave the Heat an early edge in the heavyweight second-round playoff matchup.

Wade came out firing with 23 of his game-high 38 points in the first half in Miami, and LeBron James added 22 to help the Heat grab a 1-0 best-of-seven series lead over a Celtics team that knocked each player from last year's postseason.

"Today our shot-makers made shots and that was the story," Wade told reporters after turning around his regular-season struggles against the Celtics this season when he averaged just 12.8 points per game. "These guys expect this from me. I wasn't giving it to them in the regular season versus them and I wanted to come out and be a leader. "

In the Western Conference, the visiting Memphis Grizzlies continued their magical playoff run by mauling the Oklahoma City Thunder 114-101 to draw first blood in their semifinal series.

Fresh off a shock first-round upset of the top-seeded San Antonio Spurs, the eighth-seeded Grizzlies showed no signs of a letdown against the Thunder, grabbing the lead midway through the first quarter and holding on.

A showdown between the Celtics and Heat has been anticipated ever since James and fellow All Star Chris Bosh joined forces with Wade in the offseason in an attempt to shift Eastern Conference power.

The series-opener proved feisty as Boston's Paul Pierce was ejected with two technical fouls in the fourth quarter following a confrontation with Wade.

The wily Celtics still managed to make a late push and pulled within eight points with four minutes left after having trailed by as much as 19 in the second half.

But the Heat held off the run with six straight points to move ahead 96-82 with 2:54 left

Ray Allen kept Boston in the game with 25 points, including five 3-pointers, and Pierce finished with 19.

James Jones sparked the Heat with five 3-pointers and a career playoff-high 25 points but it was Miami's defense that held Boston to 36 first-half points.

In Oklahoma City, Zach Randolph, the Grizzlies best player against the Spurs, was at it as he hit for a game-high 34 points and 10 rebounds. Marc Gasol also contributed a double-double with 20 points and 13 boards.

Kevin Durant, the National Basketball Association's scoring champion, had 33 points and 11 rebounds for the Thunder while Russell Westbrook added 29.