Sydney FC have tightened their grip on second spot in the A-League and ended Perth's unbeaten away record with a 1-0 home win at Jubilee Oval.
Adam Le Fondre's 37th-minute goal decided the cagey contest and put the Sky Blues five points ahead of third-placed Melbourne Victory.
Sydney will clinch second with a round to spare if defending champions Victory don't win at Adelaide on Friday.
Perth coach Tony Popovic made six changes to his starting side following last week's Premiers Plate clinching win.
Retiring Sydney FC captain Alex Brosque has labelled the Sky Blues' last two A-League regular season games as "must-win" matches, as they try to earn a precious rest in a hectic month.
Second-placed Sydney, who host Premiers Plate winners Perth on Thursday, hold a two-point advantage over Melbourne Victory.
Both Sydney and the Victory have to play three AFC Champions League games through May, when the A-League finals series is held, with Steve Corica's team facing two overseas trips.
Classy Sydney FC playmaker Milos Ninkovic has shrugged off the bruising early treatment he got in his side's A-League derby, which coach Steve Corica had warned his players about.
The Harbour City rivals slugged out a 1-1 draw at ANZ Stadium on Saturday, with second-placed Sydney missing the chance to put a little more pressure on ladder leaders Perth, who can clinch the Premiers Plate on Sunday with a home win over Newcastle.
Sydney hit the front through a fine seventh-minute strike from captain...