Melbourne Victory took the spoils in the Big Blue as Sydney FC dropped below their rivals in the A-League table following a 2-1 loss at AAMI Park.
Ola Toivonen's first-half free-kick and a cool finish from James Troisi after the break ensured Milos Ninkovic's effort was merely a consolation.
The result moves Kevin Muscat's side up to second, one point ahead of Sydney and one behind leaders Perth Glory, whose game in hand is at home to Newcastle Jets on Sunday.
It was a stunning set-piece from former Sweden international Toivonen that opened the scoring after 20 minutes, his sweet strike clipping Andrew Redmayne's right-hand upright on its way in.
Sydney stuck at their task but fell further behind in the 58th minute, Troisi calmly capping a swift counter-attack with what proved to be the winner.
Ninkovic ensured a tense finish, though, deftly lifting the ball over Lawrence Thomas after the goalkeeper had parried his initial effort.
Adam Le Fondre's header hit the crossbar and substitute Luke Ivanovic struck the post but the hosts held on to the three points.
Elsewhere, Wellington Phoenix secured a 1-0 win over Melbourne City courtesy of David Williams' fifth-minute strike in a match between two sides positioned comfortably in the top six.