Jimmy Butler scored 42 points as the Miami Heat staged yet another stunning comeback to send the top-seeded Milwaukee Bucks crashing out of the NBA playoffs in overtime on Wednesday.

Butler, who scored 56 points in a dazzling game four win on Monday, conjured another virtuoso display as eighth seeds Miami completed a 4-1 series triumph with a 128-126 victory.

It is only the sixth time in NBA history that an eighth seeded team has eliminated the No.1 seeds from the playoffs.

Yet the Bucks — who finished the regular season on top of the Eastern Conference with the best record in the NBA — were left ruing another fourth quarter meltdown as Miami celebrated in Milwaukee's Fiserv Forum arena.

Milwaukee, who had blown a double digit lead in Monday's game four loss in Miami, were ahead by 16 points early in the fourth quarter on Wednesday.

But with a crucial victory in sight, the Bucks' fragility was exposed once more as Miami began chipping away at the lead.

The Heat outscored Milwaukee 32-16 in the fourth quarter, with Butler grabbing a sensational alley-oop to tie the game at 118-118 with just 0.5 seconds left on the clock.

Miami then led throughout overtime with Milwaukee's Giannis Antetokounmpo giving up a costly foul with 40 seconds of overtime remaining that allowed the Heat to take a 128-124 lead.