The Sydney football club did themselves and the A-League title chasing pack a huge favour by stunning leaders Wellington Phoenix 3-0 away to leave the top four sides separated by just one point.
Former Wellington forward Shane Smetlz returned to New Zealand to haunt his old club with a goal and an assist but was sent off in the 70th minute after kicking out at Ben Sigmund.
He was the second man to see red after the hosts were reduced to 10 two minutes earlier when Albert Riera was dismissed for a second yellow card after a foul on Milos Dimitrijevic.
The result, though, was already long settled after Smeltz had headed down for Jacques Faty to emphatically smash home the opener with his right foot in the ninth minute.
Smeltz added the second after controlling a long range shot and firing a more precise effort home on the half hour mark despite Phoenix complaints for offside.
Five minutes before the halftime break, Sydney added a third after a scrappy goal-mouth scramble with Phoenix defender Manny Muscat credited with the final touch that wrong-footed goalkeeper Glenn Moss.
The Wellington coach Ernie Merrick conceded his side were second best.
"We never really got our game going in the midfield, if youn don't hold the ball in midfield you can't get your fullback forward and your wings so you're not going to set up your strikers and really that's the story of the game, the better team won they took their chances."
The Phoenix, who were missing seven players on international duty, remained top despite seeing their four match win streak end, but their lead over the Melbourne Victory, Sydney and Perth Glory was reduced to one point with four matches remaining in the regular season.
Merrick though refused to blame the international committments for his side's flat performance.
"I think the players we had were good enough to play much better football than that."
The second placed Melbourne Victory, who have a game in hand on the leaders, travel to New Zealand to face the table topping Phoenix next Sunday.
Merrick says his side will bounce back.
"That loss was the kick up the backside at the right time before you go into the finals and we've got our returning players it looks like we'll have a strong side next week."
The Victory needed two goals from Gui Finkler to secure a come from behind 2-1 win over the Central Coast Mariners on Friday.
Perth left it late to overcome reigning AFC Champions League champions Western Sydney Wanderers 3-2 with right back Josh Risdon smashing a brilliant long range effort in the 87th minute to end their nine-match winless run.
Adelaide United moved within two points of the Phoenix in fifth after Carrusca's first half effort saw off the Newcastle Jets 1-0 on Sunday.