The 2019 WNBA champion and finals MVP sunk 32 points as Belgium came from a point down at three quarter time to stun the Opals, 85-70, on Olympic Games debut.
Meesseman took the game by its horns in a dramatic final term hitting 16 points and outscoring Australia who managed just 13.
Victorian young gun Ezi Magbegor shone on Olympic debut with a team-high 20 points, eight rebounds and two blocks.
The 21-year-old credited Belgium’s performance, adding the Opals have plenty to improve on.
“Belgium are a great team, competitive. I think they were great for us to play first game to battle with and credit to them they got the win tonight,” Magbegor said post-game.
“We were a little bit stagnant on offence, that’s not how we play. In the games coming forward we need to do a better job moving the ball. I think defensively as well, playing our game and becoming great at defensive transition.
“Playing four quarters and getting back to our game will be important heading into our next match-up against China.”
Earlier, Meesseman opened scoring before Bec Allen quickly put the Opals on the board with her first Olympic points. Magbegor proved an effective focal point, quickly getting busy at both ends and scoring seven of Australia’s first 11 points.
Katie Ebzery, starting in place of the injured Steph Talbot, made an immediate impact (11 points, nine rebounds, six assists) and came close to a triple double.
The Opals went 0-4 from the field in the opening term as Belgium took a 21-17 lead into the first break.
Cayla George (12 points, 10 rebounds) hit the Opals first triple of the night to put her country ahead and it was just the beginning as the dual Olympian stamped her authority on the game with 10 second-quarter points.
She hit back-to-back triples then a two before Belgium closed within one then hit the lead through Antonia Delaere.
A trademark fade-away jumper by George built on the Opals buffer but a Delaere triple on the eve of half time put the Cats back within three at the main break, 41-37.
Allen knocked down a triple to kick off the second half and when Magbegor scored her 16th point things were looking bright.
The Cats were struggling to connect before Meesseman put an end to that as her side reeled in the margin with point guard Julie Allemand and Delaere starting to dominate.
An Aussie highlight came in the form of a triple from captain Jenna O’Hea, her first Olympic points in eight years.
Meesseman sent Belgium ahead with 90 seconds to go, three straight offensive boards then a score from Julie Vanloo had the Cats on top before Allen levelled the scores.
Free throws gave Belgium an edge before a big three from Tess Madgen breathed life into the Opals giving them a one-point buffer with a quarter to play.
Australia will look to register its first win of the tournament on Friday night when it plays China
Meesseman: 32 points, nine rebounds, five assists,
Delaere: 17 points,
Allemand: 16 points, 11 assists
Magbegor: 20 points, eight rebounds,
Ebzery: 11 points, nine rebounds, six assists,
George: 12 points, 10 rebounds
The Last Word with Kristi Harrower, 4x Olympian (2000, 2004, 2008, 2012)
“I thought the Opals were good in the first half, playing to their strength and Ezi was the offensive key. I think they went away from that in the second half. Belgium are a great team, patient, they play so well together and just keep moving.
I felt at times we needed to push the ball and get players out running or get some penetration to get our shooters open.
Their point guard, Allemand, controlled the game really well and of course Meesseman was the difference.”