Jayson Tatum (No.0) of the Boston Celtics shoots against the Milwaukee Bucks on Wednesday in Boston, Massachusetts. Photo: IC

Boston Forward Jayson Tatum banked in a game-winning three-pointer over Giannis Antetokounmpo with 1.5 seconds left to give the Celtics an 122-121 NBA season-opening victory over the Milwaukee Bucks on Wednesday.

Antetokounmpo, the two-time defending NBA Most Valuable Player, had a chance to tie it from the free-throw line with four-tenths of a second left, but the Greek superstar missed his second free throw after being fouled at the rim and the Celtics came away with the win on their home floor.

Tatum finished with 30 points but connected on just 12 of 28 shots from the floor.

Jaylen Brown led the Celtics with 33 points, five rebounds and four assists

Antetokounmpo, who last week signed a five-year contract extension reportedly worth a record $228 million, led Milwaukee with 35 points, 13 rebounds, two assists and two blocked shots.

The nail-biter in Boston was one of a dozen games on the second night of the 2020-21 season.

It was supposed to be 13, but Houston's home opener against the Oklahoma City Thunder was postponed as COVID-19 concerns - including James Harden's violation of anti-virus protocols that cost the superstar a $50,000 fine - left the Rockets with less than the required eight players available to stage the game.

Harden was ineligible after the league found he attended a party on Monday in violation of protocols prohibiting players from attending indoor gatherings of more than 15 people.

The Rockets also had three players return positive or inconclusive coronavirus tests, and four other players were isolated due to contact tracing.

It was a sooner-than-expected jolt for a league that managed to crown the Los Angeles Lakers champion in a quarantine bubble in Florida just over two months ago but is now launching a season in which teams are playing in their home arenas as coronavirus cases continue to surge.

One day after the Lakers launched their title defense with a loss to the LA Clippers, the Miami Heat - who fell to the Lakers in the championship series - were also beaten.

Evan Fournier scored 25 points for Orlando and the Magic downed the Heat 113-107.

Terrence Ross scored 19 points and Nikola Vucevic and Markelle Fultz ­added 15 points each for the Magic.

Russell Westbrook impressed in his Washington Wizards debut, notching the first triple-double of the fledgling season with 21 points, 11 rebounds and 15 assists for his new team who nevertheless fell 113-107 to the Philadelphia 76ers.

Westbrook, traded to Washington by the Rockets for John Wall, notched the 147th triple-double of his career as he chases Oscar Robertson's record of 181.