In one of their most polished attacking displays of the season, the Sky Blues hammered Perth 6-0 at Allianz Stadium on Saturday night - a scoreline coach Graham Arnold predicted before the game.

"I kept saying to them this week that we will win 6-0. It's about believing it," Arnold said. "I wrote it on the board. Go and have a look at the board. I wrote on the board 6-0."

A hat-trick for Brazilian striker Bobo - his second in as many games - and goals for Adrian Mierzejewski, Brandon O'Neill and Alex Brosque made Arnold appear prophetic as the Sky Blues made light work of Perth Glory.

It moved Sydney FC to 34 points after 13 games, one point ahead of this time last year when they broke almost every record on offer in an A-League season where they won the domestic double. Their whitewash of the Glory made it 18 goals in just four games and extended their home undefeated streak to 23 games, equalling the A-League record for home form set by Brisbane Roar seven seasons ago.

It was an incisive counter-attack that put the champions on course for another three points at home. Midway through the first half, Mierzejewski lead the break-away through the middle of the park and used his experience to draw in Perth's backline, before slipping a clever through ball for Milos Ninkovic. The Serbian generously passed to O'Neill, who slotted the ball into an empty net to open the scoring.

Finding their fluency was the main objective of Graham Arnold's half-time team talk and Sydney FC emerged more calm and composed after the restart. A quick exchange down the spine unravelled Perth's defence and the in-form Mierzejewski seized on the space, rounding Liam Reddy to tap-in a second. However, his muscle-pose celebration was cut short after an astute linesman spotted an offside.

It only delayed the inevitable. Two minutes later, the Polish international had his reward. His sixth goal in as many games required a hint of fortune as his curling left-foot shot from inside the box was deflected past Reddy to make it 2-0.

Four minutes later, the result was sealed. Captain Brosque scored Sydney's third with an exquisite, deft header, guiding Michael Zullo's cross past Reddy into the far corner of the net to send the home fans into raptures and Perth staring down the barrell of yet another hefty defeat at the expense of the Sky Blues.

That fate was made certain just five minutes later. Perth defender Jacob Poscoliero gifted Sydney a chance to make it 4-0 when he pulled down Bobo inside the box, and the league's top marksman scored his 11th of the season from the penalty spot.

They weren't done yet. Had it not been for five late saves by Reddy against Luke Wilkshire, O'Neill, Mierzejewski, Bobo and Charles Lokolingoy, Sydney's lead would have swelled to disrespectful proportions for the Glory.

There was nothing Reddy could do to deny a Bobo masterpiece on the stroke of full-time, however. His half-volley with his back to goal made it 5-0.

A 95th minute foul by Reddy on Bobo gave the Brazilian a chance to seal his hat-trick and score his 13th goal in as many games with a penalty. He did just that via the upright, making it 6-0.

If Sydney FC beat second-placed Newcastle Jets on Wednesday night at home and open an 11-point gap at the top, the race for the Premiers' Plate could be all but over.