But proving results aren't everything, defending champions Central Coast and top-placed Brisbane Roar also recorded their lowest crowds this season.
Head of the A-League Damien De Bohun however, is not concerned with the dip in numbers - which are nowhere near as bad as the lowest ever regular-season round figure of 22,729 recorded in round three of the 2006/07 season - and says the figures still show the fanbase is continually growing.
"This week was down a bit but given where the games were played and also the weather and some of the performances it wasn't a massive surprise to us,'' he told AAP on Monday.
"The really big rounds are always going to be when the big clubs have home games and there's derbies and big fixtures and we obviously start off the season quite deliberately with certain fixtures to build momentum.
"But we're very pleased with the way the season's travelling, the broadcast and crowd numbers are still considerably up from last year collectively.''
The Sky Blues set a record crowd of 40,388 for the first Sydney derby of the season against Western Sydney in round three - their biggest-ever home attendance for a regular-season match.
The second of three Sydney derbies this season is sure to sell out 21,000-seater Parramatta Stadium on January 11 while Melbourne Victory hosting the Wanderers at AAMI Park in late December then again in mid January should also draw big crowds along with the second Melbourne derby on December 23 at the same venue.
And De Bohun is confident big games like these will show a spike in numbers over the next few rounds.
"If you look at the fixtures ahead of us we expect that to bounce back pretty quickly,'' he said.
"We have those big fixtures spread out through the season to get that balance right.''
- AAP