Wanderers coach Popovic was on Saturday given a suspended two-match ban from AFC Champions League matches as a result of an altercation during the quarter-final first leg against Guangzhou Evergrande.
AFC Coach of the Year Popovic was also fined $2,000, and his day went from bad to worse as United ensured last year's runners-up remain bottom and still without a win after nine matches.
The Champions League holders were always going to be up against it after Nikolai Topor-Stanley was sent off only 17 minutes in as a result of two bookings in as many minutes.
Captain Torpor-Stanley was cautioned for a tussle with Bruce Djite before being dismissed soon after for deliberate handball and he was made to pay as the hosts dominated.
Fabio Ferreira opened the scoring with his first goal of the season when he turned in Sergio Cirio's cross nine minutes before half-time and Marcelo Carrusca doubled Adelaide's lead 10 minutes after the break with a fine strike.
Carrusca exchanged passes with Ferreira before finding the top corner of the net and there was no way back for Popovic's side, who now head off to the FIFA Club World Cup in Morocco devoid of confidence.
Newcastle Jets are also without a win after they suffered their fifth defeat of the campaign at home to Wellington Phoenix.
The Jets looked set to get that elusive first victory after Joel Griffiths put them in front 24 minuets in, but three goals in the space of five minutes in the second half consigned them to defeat at Hunter Stadium.
Nathan Burns levelled 17 minutes from time and Michael McGlinchey put the visitors in front a minute later before Roy Krishna added a third to compound the Jets' misery.
