Macarthur FC cranked up the pressure on Western Sydney Wanderers coach Carl Robinson after they claimed a 2-0 win in the A-League Men.
A second-half finish from defender Tomislav Uskok broke the deadlock after an hour of play before substitute Jake Hollman netted in the 74th minute to seal victory for Ante Milicic's men.
Robinson lost in the FFA Cup to NPL side APIA Leichhardt on Tuesday with a rotated team, but the nature of the defeat to Macarthur, who remain top of the ladder, will have done nothing to silence his detractors.
The Wanderers were shorn of creativity and despite having 65 per cent of the ball, did little to give the crowd of 8910 at Commbank Stadium anything to cheer about.
Robinson, whose side were booed off at fulltime, were without Jack Rodwell and Tomer Hemed after they picked up knocks in the Wanderers' unconvincing win over Wellington last week.
Bernie Ibini was picked to lead the line and he enjoyed a running battle with new Macarthur recruit Adrian Mariappa. He got the better of the Jamaican international early on when he darted into the box but could only lash a shot at Filip Kurto from a tight angle.
The Bulls sat deep and invited Western Sydney to attack but the home side were unable to engineer a breakthrough.
Macarthur were restricted to hitting the Wanderers on the break and their best opportunity of the first half came with half an hour gone.
Tommy Oar had Western Sydney goalkeeper Tomas Mejias beaten at his right post from some distance, only for the ball to cannon off the woodwork and out for a goal kick.
The second half began in lively fashion when Macarthur's Craig Noone copped a stray elbow from Dimi Petratos and the Wanderers had a penalty appeal turned down after Charles M'Mombwa appeared to handle the ball in the box.
There was no penalty forthcoming for the Wanderers, but they should well have gone ahead with James Troisi only able to fizz a shot beyond Kurto's reach but past the keeper's left-hand post.
They were opportunities the Wanderers would come to regret when a rebound corner was worked to Daniel de Silva on the Macarthur left in the 64th minute.
De Silva's cross was flicked on by Lachlan Rose and, after his first attempt was parried by Mejias, Uskok hammered home on the second time of asking to put the Bulls ahead.
It was a smash and grab effort from Macarthur, but they extended their lead when Rose again linked with De Silva on the counter
A backheel from the striker found De Silva who played Hollman in on goal, with the substitute cooly finishing past Mejias to ensure Macarthur's unbeaten start to the season remains intact.