Khris Middleton nailed a clutch two-pointer with less than one second remaining as the Milwaukee Bucks snatched a thrilling 109-107 overtime victory against the Miami Heat in their NBA Eastern Conference playoff opener on Saturday.

Middleton kept his composure superbly to drain the decisive jump shot from 18 feet with just 0.5 seconds on the clock, handing the Bucks a 1-0 lead in the best-of-seven first round series.

Middleton's dramatic winner marked the final act of a pulsating battle between the two Eastern Conference rivals, who also met in last year's playoffs with the Heat winning that series 4-1.

Heat talisman Jimmy Butler had taken the game to overtime at the end of the fourth quarter, driving to the basket to make it 99-99 as time ran out at Milwaukee's Fiserv Forum.

But Middleton's late winner settled the game in overtime and gives the Bucks the chance to take a grip on the series with game two at home on Monday.

Middleton led the Bucks scorers with 27 points, six rebounds and six assists, with Giannis Antetokounmpo, who appeared to be struggling with a sore left arm, adding 26 points with 18 rebounds and five assists.

The Bucks were almost left to rue another shaky performance from the free throw line from reigning NBA MVP Antetokounmpo, who made only six of 13 free throw attempts for a 46.2% completion percentage.

Jrue Holiday added 20 points for Milwaukee while Brook Lopez finished with 18 points as the Bucks scraped home.

"It's a good start," Middleton said afterwards. "A lot of mistakes, a lot of missed free throws, lot of threes from them, and we missed threes. But it's a great start to what we want to do and where we want to be."

Doncic stars for Mavs

Middleton, meanwhile, praised Antetokounmpo for battling through an uneven personal performance.

"I don't think he had his night the way he wanted to," Middleton said. "But he battled, and defended well and that's what he's supposed to do -- when it's not your night, do other things."

Antetokounmpo meanwhile was relieved that Middleton was able to get the Bucks over the line.

"Thats what he does," Antetokounmpo said. "Having a guy like Khris down the stretch, you know what's he going to do."

Goran Dragic led the Miami scorers with 25 points, while shooting guard Duncan Robinson finished with 24 points. Butler, the star of Miami's run to the NBA Finals last season, finished with 17 points.

In other opening playoff action on Saturday, the fifth seeded Dallas Mavericks rallied late in the fourth quarter to down the fourth-seeded Los Angeles Clippers 113-103 at the Staples Center.

Mavs star Luka Doncic scored a 31-point triple double with 10 rebounds and 11 assists as Dallas pulled away to win after trailing by three points with five minutes remaining.

Tim Hardaway Jr. had 21 points while Dorian Finney-Smith added 18 as the Mavs took a 1-0 series lead against the Clippers, who beat Dallas in six games at the same stage of the playoffs last season. 

"I hope it's going to be different this time, I hope it's not going to be the same story," Doncic said afterwards. "I forgot how much fun it was to play in the playoffs."

Kawhi Leonard led the Clippers scorers with 26 points, with Paul George adding 23.

In other games Saturday, the Brooklyn Nets face the Boston Celtics, while the Denver Nuggets host the Portland Trail Blazers in the late Western Conference game.