The presence of tropical cyclone Hamish off the north Queensland coast meant Cazaly Stadium was subjected to a torrential downpour for most of the NAB Challenge game.
However, the Demons made the most of the dismal conditions to win 11.7 (73) to 4.12 (36).
Voss admitted the Lions had struggled to cope with the rain and both defenders and forwards needed to improve as the season progressed.
"There are some things over the course of the year that we've got to improve to become an elite side," he said.
However, he said he had taken positives from the match, including the return of captain Jonathan Brown.
"I don't think there's necessarily anything gaping there but we'll have to sit back and have a look at the tapes," he said.
Brown made his first appearance since undergoing minor knee surgery last year. He put in a solid performance, kicking one goal before being taken off at half time.
Brown is expected to play a full match against Richmond on the Gold Coast next weekend.
"He moved pretty well and I think he got a about the right (match) time that we needed him to play and he can obviously step it up against Richmond next week," Voss said.
Melbourne coach Dean Bailey was happy to walk away with a win but there was still work to do before the season kicked off.
"It's always good to get a win but the Lions guys had bested a few of those blokes at half time," he said.
"But we still played well enough to win the game so that's a good reward for the guys."
Melbourne 2.1 6.3 10.3 11.7 (73)
Brisbane Lions 2.3 2.5 4.7 4.12 (36)
GOALS
Melbourne: Newton 3, Petterd, Dunn 2, Jetta, Moloney, Bruce, Jones.
Brisbane Lions: Clark, Brown, Hooper, Dalziell.
BEST
Melbourne: Newton, Warnock, Dunn.
Brisbane Lions: Johnstone, Adcock, Dalziell.
Injuries
Melbourne: Nil.
Brisbane Lions: J Brennan (quad).
Umpires: H Kennedy J Mollison B Ryan.
Crowd: 4,000 approx. at Cazaly Stadium.
