Kosta Petratos scored a stoppage-time winner as Newcastle Jets prevented Sydney FC from clinching the A-League Premiers' Plate with a 2-1 victory at Jubilee Oval on Tuesday.

The Sky Blues only needed a point to be guaranteed top spot, but suffered just a third league defeat of the season.

Anthony Caceres put the defending champions in front from close range after 25 minutes, but the Jets stormed back to keep their finals hopes alive with three games to play.

Nick Fitzgerald equalised in style with a volley and Petratos won it with time almost up, turning before firing into the far corner from just outside the penalty area.