Western Sydney Wanderers improved their hopes of landing a Finals place with a huge victory, while Sydney FC had a more difficult day.
Bruce Kamau, Mitchell Duke and Scott McDonald got the goals as Western Sydney Wanderers beat neighbours Sydney FC 3-2.
Sydney FC are only point point behind Melbourne City after beating the A-League leaders' struggling local rivals.
Just four points separate the top five teams in the A-League after both of Saturday's games ended in score draws.
Melbourne City, who won 7-0 on Saturday, remain top of the A-League after Adelaide United could not beat Sydney.
Jamie Maclaren is now second on the all-time A-League top scorers list, while Melbourne Victory ended a six-game wait for a win.
Perth goalkeeper Liam Reddy made nine saves but was not quite able to keep out Sydney FC's winner on Wednesday.
Kosta Barbarouses scored one and assisted another against former side Melbourne Victory as Sydney FC eased to a 3-0 win on Sunday.
Craig Goodwin's 76th-minute penalty was enough for in-form Adelaide United to triumph again in the A-League on Sunday.
Melbourne Victory stayed four points adrift at the bottom of the A-League after Wellington Phoenix stormed to a 4-1 win.