Brooklyn Nets head coach Steve Nash was not happy with his team's performance after the NBA title-chasing franchise were blown away by defending champions the Milwaukee Bucks on opening night.

After unveiling their banner and championship rings in a pre-game ceremony, Giannis Antetokounmpo fuelled the Bucks to a 127-104 rout following his double-double on Tuesday.

Kevin Durant had 32 points and 11 rebounds and fellow Nets superstar James Harden put up 20 points, eight rebounds and eight rebounds as he flirted with a triple-double on the road, while Patty Mills (21 points on seven-for-seven shooting from beyond the arc) tied the NBA record for most made threes on debut for a new team.

But the Nets were no match for the Bucks in a repeat of last season's Eastern Conference semi-final after being outscored 37-25 in the opening period.

"We weren't very good," Nash said. "If you're not playing at a high level against the champs, you're not going to win."

It was a tough start to the season for Durant and Nets, who were without All-Star Kyrie Irving amid his absence because of not being vaccinated against COVID-19.

"We can’t give a team 20 more shots than us," Durant told reporters after the Bucks made 48 of 105 shots, while the Nets finished 37-84 from the field. "Imagine coming to a game and say 'here, take the ball 20 times on offense before we get an offensive position.

"This is one game out of 82 of them. We'll look at it that way. Every team will look at it that way. The Bucks won today, but they're still trying to fine-tune what they do, too.

"I think every team in the league is going to look at their first few games, first few weeks and see where their team is going and then make adjustments."

During preseason, Durant called the Bucks – spearheaded by Antetokounmpo, Khris Middleton and Jrue Holiday – a dynasty after they ended their 50-year wait for a championship in 2020-21.

But after Tuesday's showdown, the former MVP told reporters: "Maybe I was reaching a little bit.

"I just look at it as it's hard in the league for four or five guys to stay together as long as the Bucks did, through the ups and downs of losing in the first or second round, almost going to the Finals in 2019.

"They've been through a lot together. That's probably what I meant more than anything."

"They're just a team with some continuity," former Golden State Warriors forward Durant added. "I take that 'dynasty' thing back. I know it's a lot how that word gets thrown around. But they have some continuity a lot of teams don't have."