United capped a dominant season by closing out a 3-0 sweep of the injury-ravaged Wildcats with an 81-76 victory at John Cain Arena on Friday but they were pushed to the brink after seeing a 16-point advantage wiped out by the visitors.

But the home side steadied during a tense final quarter thanks to Grand Final MVP Jock Landale with Japanese international Yudai Baba kicking off the celebrations with a dunk in the final three seconds to seal the victory.

Melbourne's stockpile of high-end talent saw them labelled as title favourites leading into the 2021 campaign but the journey was far from smooth with 12 players testing positive for COVID-19 during the preseason.

"This group absolutely earned it," Vickerman said after claiming his third championship as a head coach.

"They sacrificed like every other team in the league but this was a group that had COVID at the start of the year. We went through that whole thing ... and from that point, we came together as a group."

COVID restrictions saw United complete an 11-match road stint before returning home to host their first grand final clash but a run of seven wins in the past eight games handed them the opportunity to win the trophy in front of a reduced-capacity crowd of 5,000 fans.

"To celebrate at home, it still felt like it was pretty packed tonight even though it was half full but it was amazing to win a championship on your home floor," Vickerman said.

The home side surged ahead 25-9 but Perth shut down Melbourne's attack and won the rebounding battle to grind their way to the lead in the third quarter.

But the Wildcats had no answer for Landale in the final term as United ended their shot at a third consecutive championship.

While disappointed with the result, Perth coach Trevor Gleeson expressed pride in his injury-battered squad for fighting all the way to the end without three-time league MVP Bryce Cotton.

The timing of Cotton's season-ending leg injury left Gleeson scrambling to reorganise Perth's offence with a hip problem for starting point guard Mitch Norton making the task even harder.

"Bryce goes down so we have four or five games to get organised and do something else at the back end of the season and then just the injuries compounded," Gleeson said.

"We just didn't have enough time to get our peak at the right time but we certainly played with our passion and our pride - those things are irreplaceable."

Australian Associated Press