MILWAUKEE - The Knicks had so many long nights last year, so many games where they were overmatched and underwhelming. In their regular-season opener, they looked nothing like that team.

Their overhauled roster played with passion and played together, and their new and improved second unit rescued their starters Wednesday night, sparking the Knicks' impressive and unexpected opening-night 122-97 rout of the Bucks.

It was Carmelo Anthony's first game since having knee surgery in February and rookie Kristaps Porzingis' first-ever NBA game. Both men started slowly and spent parts of the game jumping out of their seat to cheer on their backups.

Derrick Williams led the Knicks with 24 points, and Langston Galloway added 16, and shot 4-for-5 from three. The Knicks' reserves outscored their starters 73-49.

Porzingis only shot 3-for-11, but he played aggressively and attempted 12 foul shots. He finished with 16 points and five rebounds in his NBA debut. Anthony was 4-for-16 with 11 points, six rebounds and five assists.

The blowout enabled Anthony to play just 30 minutes, which could keep him fresh for Thursday night when the Knicks play their home opener against the Hawks.

Greg Monroe, a Knicks' free-agent target, had 22 points and 14 assists for the Bucks, who were without Giannis Antetokounmpo (suspension) and O.J. Mayo (hamstring).

The Knicks, who were a franchise-worst 17-65 last season, were totally reconstructed in the last 12 months. Only six players returned from last yea's team, and just three were on the opening-night roster.

Team president Phil Jackson spent roughly $90 million on Robin Lopez, Arron Afflalo, Kyle O'Quinn, Williams, Sasha Vujacic and Kevin Seraphin.

The Knicks didn't land any stars to put next to Anthony with the near $30 million they had to spend in free agency. But Anthony got the help he needed Wednesday night.

O'Quinn grabbed 11 rebounds. Lance Thomas shot 5-for-5 and scored 13 points and rookie Jerian Grant had 10 points and five assists.

The Knicks were supposed to be improved defensively. Yet the Bucks got inside easily in the first quarter and Monroe dominated the boards early. But Williams, O'Quinn and Grant sparked a 15-0 run with their activity and defense.

The second-unit turned the Knicks' early seven-point deficit into a 12-point edge 3:31 into the second quarter. The lead extended to 59-43 later in the second with some subs still on the floor.

Williams had 15 points in the first half and O'Quinn eight points, nine rebounds and two blocks. The second team outscored the starters 38-25 in the opening half.

Derek Fisher stayed with the same starting five to open the second half, and they pushed the advantage to 77-55 after a Porzingis' hook shot with 7:19 left in the third. Later in the third, the Knicks still led by 18 following back-to-back three-pointers by Porzingis and Langston Galloway. Anthony found both of them for the wide-open threes. Galloway drilled two more threes before the quarter ended with the Knicks on top 90-73. Anthony struggled with his shot, but he had been waiting for this moment since undergoing left knee surgery eight months ago. He was trying to keep his emotions in check and "stay mellow" because there was a time he wasn't sure if he would be back for opening night.

"To be able to open up a season opener for us is hell of a story for me," Anthony said.

It didn't begin well for Anthony or the rest of the Knicks starters. But the second unit bailed them out, and helped turn around the game. Anthony was just 2-for-9 in the first half with five points but the Knicks led 63-51.

It wasn't until last week that Anthony's rehab officially ended, and everyone breathed a sigh of relief. That probably happened before last week, though, since Anthony said the training staff knew they were under the microscope.

"I'm pretty sure they were excited because there was a lot of pressure on them coming from the front office to get this right," Anthony said. "We were just glad to see everything came to fruition and kind of exhaled a little bit."

The Knicks could say the same about their opener.