Brisbane have shown just why they’re the A-League leaders, posting a commanding 5-2 victory over Sydney FC at Allianz Stadium.

Front-runners Brisbane became the first A-League team to reach 100 victories and did it in commanding style on Boxing Day with a 5-2 drubbing of Sydney FC.

Skipper Alessandro Del Piero broke the deadlock on Thursday night but the Sky Blues conceded two penalties to help Dimitri Petratos to a hat-trick.

Thomas Broich and Ivan Franjic rounded out the scoring for Brisbane before Richard Garcia got one back in the dying minutes at Allianz Stadium.

With the average age of 30 it was the oldest team Sydney have ever fielded and it showed.

The Roar dominated play from the get go with their attacking, passing football providing a stark contrast to a sluggish looking Sydney who lacked any real fire-power up front.

Del Piero and fellow veteran Brett Emerton were both back after missing last week’s loss to Wellington.

And 39-year-old Del Piero again proved the difference for the Sky Blues.

Roar defender Jade North conceded a free-kick after bringing down Del Piero just outside the box and the Italian made no mistake, his inch-perfect strike beating the wall and out-stretched keeper Michael Theo to put the hosts in front in the 11th minute.

But Brisbane playmaker Broich found the equaliser just nine minutes later with a great strike, timing his run to perfection to get on the end of a superb through-ball from Luke Brattan.

Sebastian Ryall then gifted the Roar a penalty a moment later with a foul on Henrique in the box.

Petratos, in his first start against his former club, stepped up to the mark and slotted home but was forced to re-take the penalty kick.

His second attempt was no different, too good for keeper Vedran Janjetovic, to put the visitors in front 2-1 in the 23rd minute.

Petratos got his second of the game in the 35th minute, courtesy of great lead-up work from Broich, to send the visitors to the break 3-1 up.

The Roar looked to have gone 4-1 up early in the second half when Henrique headed home but the goal was disallowed with the referee picking up the Brazilian’s handball.

The Roar were awarded another penalty in the 77th minute when Nikola Petkovic charged at Broich in the box, with Petratos netting from the spot to get his treble.

Franjic put the final nail in the coffin with his extra-time strike before Garcia got one back just before the final whistle.

“We were shown a football lesson tonight, there’s no hiding from that fact,” Sydney coach Frank Farina said.

“They were the better team, they were more mobile, moved the ball better and we couldn’t cope with it.

“We were slow in getting close to players and they could pick us off.

“I just don’t think we were at the races today on all fronts.”

Farina was again left sweating the fitness of marquee Del Piero, who again was unable to last a full game, going off at the break with tightness in his lower back.

“It’s unfortunate Alessandro had to go off at halftime again, but that’s life,” he said.

“I think it’s a similar thing whether it’s his back or whatever, but things tightened up.”

Roar coach Mike Mulvey was missing super-boot Besart Berisha (hip) but praised the side’s performance without their main attacking weapon.

“We have one of the best strikers in the land, he’s at home and we scored five and it could’ve been eight,” he said.

“I thought it was a very dominant display.

“Some of the football was just beautiful to watch and it was a joy to see the interpassing and the interchanging of positions and the finish at the end of it.

“Thomas (Broich) was the orchestrator tonight and he had players running off him all over the place.”