While this was an understated affair and not recognised as an official T20, with both sides able to select as many of their 15-strong squads as they wished, it was England who will walk away happiest.
Ben Stokes, who had underwhelming returns in the recent series win against Australia, showed flashes of his best with 36 off 18 balls, igniting England's successful pursuit of 161 after they lost openers Phil Salt and Alex Hales cheaply - with Buttler and Dawid Malan deciding not to bat on Monday.
Liam Livingstone marked his return from an ankle injury by taking one for eight from two overs before thumping 28 off 16 balls in England's chase, including one towering six that cleared the Gabba.
Harry Brook (45 not out off 24) and Sam Curran (33no off 14) then helped England to a commanding victory with 26 balls to spare, just five days before they start their World Cup against Afghanistan at Perth.
"We just wanted to get certain things out of the game and we got all of those things," said Buttler, whose side were helped by several fielding errors and dropped catches from their opponents.
"It was great to see (Ben) play so well, he's been hitting the ball so well in the nets and we know what a dangerous player he is, so I'm sure he'll take a lot from that outing he got.
"It was great to see Liam Livingstone back on the field after a significant injury. Brook and Curran got some time out in the middle as well."
England used eight bowlers after electing to field first - they were asked to bat in all three matches against Australia as they lost the toss - and only Chris Jordan completed his four-over quota.
It was only Jordan's second match on his comeback from a broken finger and he showed his prowess at the back end of an innings by conceding just two runs in the final over to finish with one for 36.
"Obviously we've batted first in the three games against Australia so we just wanted to try to restrict them first with the ball," Buttler added.
"We tried a few different things with the ball that guys were wanting to experiment with and this was the perfect time to try them. I think everything we wanted to get out of (playing here) we did."