The 29-year-old's every touch was mercilessly booed by certain sections of the Melbourne crowd in the early stages of the game, but his impressive showing meant the abuse subsided during a first half that saw Manchester United's Anthony Martial score in a third successive friendly.
The Frenchman was involved in an excellent team goal finished off by Marcus Rashford early in the second half and flicked through for Jadon Sancho to finish another well-worked move.
David De Gea will be disappointed not to have kept out Joel Ward's header and Will Fish was sent off but it was another largely positive night for new-look United.
Donny van de Beek acknowledged that Maguire showed "big personality" with his impressive reaction to the catcalls.
"I heard as well," said the Holland international. "I didn't know really what happened.
"But I think if I saw the game today I think Harry was playing really well.
"He was aggressive, he got so many balls, so that means he has a big personality.
"He has a lot of experience, so I think that's positive what he (showed), his performance today."
Some of Erik ten Hag's fingerprints are already visible in United's approach - tactics Van de Beek knows better than most having worked under him with great success in Ajax.
Asked what the manager is trying to make the group do, he puffed his cheeks and said: "So many things. But I think he likes the details as well and he asks a lot from you as a player.
"You have to be fit to play his style of football but I think we have the right players for that.
"We just have to keep going and repeat all the time and then we will improve I'm sure.
"I mean, in the pressure you could see already a bit different things than before but also in building up, a lot of variations.
"I think still we can improve a lot of things but, yeah, it seems like positive and we just need to keep going and train good."
Put to Van de Beek that he must have been happy to hear his old manager was being appointed by United, he said with a smile: "Yeah, I don't know. Of course they say that because I had him in Ajax.
"But, again, you know, in the end you have to play good for him from yourself and it doesn't make any sense who is the coach. You need to find your role in the team.
"Of course he knows me as a player but, still, that says nothing, you know? I have to show it for myself."
Van de Beek may have struggled to fulfil his potential in a United shirt so far but the constant backing from fans has not gone unnoticed.
"I think, yeah, that's positive that they like me," he added.
"They know I will always give everything and, yeah, I hope one day I will give them something back.
"But it gives you confidence as well and it's a good feeling."