Ola Toivonen scored on his first A-League start for Melbourne Victory as a Keisuke Honda penalty sealed a 2-1 win over rivals Sydney in Sunday's 'Big Blue', while leaders Perth Glory beat Central Coast Mariners late on to go four points clear.
Sydney – table-toppers at the end of the 2017-18 regular season – welcomed the Grand Final champions looking to avenge their defeat in last April's play-off semi-finals, but Victory left Jubilee Stadium triumphant once again.
The early exchanges were even before Victory edged ahead in the 23rd minute – Toivonen finding the bottom-right corner from the edge of the box following good play by James Troisi.
Sydney levelled just after the half-hour mark, as Terry Antonis felled Paulo Retre in the box and Adam Le Fondre scored on the rebound after seeing his initial penalty saved.
The second spot-kick of the match ultimately settled the contest.
Honda was sent tumbling by Jop van der Linden and the Japanese midfielder converted to seal the points and inflict a first defeat of the season on Sydney.
In the day's later kick-off, rock-bottom Mariners could not hold on to what would have been a commendable point away to Glory.
A Tomislav Mrcela own goal nine minutes before the break cancelled out Christopher Ikonomidis' well-worked Glory opener.
Shane Lowry put Glory ahead again in the 61st minute when meeting a cross, but Aiden O'Neill – on loan from Burnley – found the top-left corner with a stunning 25-yard strike soon after.
Mariners' Kalifa Cisse was given his marching orders in stoppage time for a late tackle on Ikonomidis, and the Glory midfielder capitalised soon after, netting the last-gasp winner from close range after Neil Kilkenny's fine cross.