The Hyundai driver cruised to a comfortable fifth victory of the season in changeable conditions to move more than a race win's worth of points clear of nearest rival Esteban Guerrieri.
Light rain as the cars headed to the grid gave teams a headache over which tyres to fit, particularly when that intensified, though most, including polesitter Michelisz, opted for a combination of slick front tyres and wet rears to deal with the slippery surface.
Officials decided to start the race behind the safety car, though this was called in at the end of the first lap - with Michelisz deciding to hit racing speed halfway down the back straight.
Michelisz duly gapped his nearest pursuer Aurelien Panis by two seconds in the opening laps, and would end up 2.446 seconds clear of the Comtoyou Cupra driver - who scored his first WTCR podium - at the end of the extended 10-lap race.
Gabriele Tarquini backed up BRC Racing teammate Michelisz's win by taking third, finishing a distant 7.563s behind Panis, ahead of Guerrieri.
On a dramatic opening lap, Guerrieri fought his way forward from ninth on the grid to seventh thanks to passes on Comtoyou Audi driver Frederic Vervisch and, after a tussle in the third sector, the Team Mulsanne Alfa Romeo of Ma Qing Hua.
The Argentinian then dived past Hyundai man Augusto Farfus at the first corner at the start of lap three, and past Nestor Girolami and Mikel Azcona - struggling for grip on full wet tyres - at the Turn 9 hairpin the following lap.
That was the extent of Guerrieri's progress, though the result did limit his loss to Michelisz and also moved him slightly further clear of Yvan Muller, who finished sixth.
Muller made even more impressive progress through the field from his 16th-place starting position, though his progress was thwarted by the KCMG Honda of Joao Paulo de Olivera.
The 2010 Formula Nippon champion advanced from 13th to finish fifth, setting the fastest lap in the process, though his wildcard status means he is ineligible for points.
That means Guerrieri sits 27 points behind Michelisz with two races remaining, with Muller - now the final remaining title contender after his Cyan Racing Lynk & Co teammate Thed Bjork was eliminated from contention - eight further back.
|1||5|| Norbert Michelisz ||Hyundai||10|
|2||21|| Aurelien Panis ||CUPRA||10||2.446|
|3||1|| Gabriele Tarquini ||Hyundai||10||10.009|
|4||86|| Esteban Guerrieri ||Honda||10||10.878|
|5||38|| Joao Paulo ||10||11.287|
|6||100|| Yvan Muller ||Lynk & Co||10||12.125|
|7||37|| Daniel Haglof ||CUPRA||10||17.213|
|8||14|| Johan Kristoffersson ||Volkswagen||10||20.142|
|9||88|| Nick Catsburg ||Hyundai||10||31.331|
|10||69|| Jean-Karl Vernay ||Audi||10||31.772|
|11||111|| Andy Priaulx ||Lynk & Co||10||36.466|
|12||25|| Mehdi Bennani ||Volkswagen||10||37.211|
|13||9|| Attila Tassi ||Honda||10||40.633|
|14||68|| Yann Ehrlacher ||Lynk & Co||10||42.004|
|15||52|| Gordon Shedden ||Audi||10||43.183|
|16||33|| Benjamin Leuchter ||Volkswagen||10||45.377|
|17||96|| Mikel Azcona ||CUPRA||10||58.401|
|18||55|| Ma Qing Hua ||Alfa Romeo||10||1'00.734|
|19||27|| Mitchell Cheah ||Hyundai||10||1'03.709|
|20||31|| Kevin Ceccon ||Alfa Romeo||10||1'05.014|
|21||10|| Niels Langeveld ||Audi||10||1'07.607|
|22||29|| Nestor Girolami ||Honda||10||1'10.078|
|23||12|| Rob Huff ||Volkswagen||10||1'17.382|
|24||50|| Tom Coronel ||CUPRA||10||1'20.508|
|25||15|| Hafizh Syahrin ||Hyundai||10||1'24.275|
|26||65|| Douglas Khoo Koh Hui ||CUPRA||10||1'36.373|
|27||11|| Thed Björk ||Lynk & Co||10||2'02.312|
|28||8|| Augusto Farfus ||Hyundai||10||2'22.601|
|18|| Tiago Monteiro ||Honda||6|
|22|| Frederic Vervisch ||Audi||2|
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