Bulls striker Duke shrugged off concerns over a hamstring strain and flaunted his dangerous best at Campbelltown Stadium, notching an assist to go with his goals in the 10th and 68th minutes on Thursday night.
Refusing to give up on making a second World Cup appearance, the 50-cap Socceroo's standout performance comes after missing out on a spot in national team boss Tony Popovic's 26-strong squad for friendlies against Cameroon and Curacao last month.
The 35-year-old Duke sent a scare through the Bulls camp after appearing to injure his hamstring and coming off in the 74th minute, but the club said it was a regulation substitution for Harrison Sawyer.
Duke helped sixth-placed Macarthur keep their finals hopes alive, notching back-to-back wins after going winless in their previous six fixtures.
Mark Milligan's Jets boast a five-point lead ahead of second-placed Auckland FC's clash against Adelaide on Friday, after fumbling a first-half brace from rising youngster Xavier Berntoncello.
Eli Adams, who came off the bench after halftime, had scored in the 55th minute but was found offside.
The Jets were also denied a penalty in the 86th minute, with Bulls youngster Luke Vickery found to have fouled left-back Dan Wilmering outside the box.
Another hamstring injury to luckless Thomas Aquilina only adds to Newcastle's woes, with the defender forced off in the 79th minute.
Macarthur started the better side and should've drawn first blood in the fifth minute if Chris Ikonomidis hadn't wasted a quality header assist from Duke.
But Duke was able to nail the perfect start for the home side less than five minutes later after a lapse in Newcastle's defence left him alone in the box.
Set up by a brilliant header from Rafa Duran, Duke pivoted and hammered the ball past Jets goalkeeper James Delianov.
Bertoncello replied for Newcastle with a dashing run down the corridor just three minutes later, but Duke returned the favour for Duran in the 24th minute to restore their lead.
Bulls coach Mile Sterjovski cut a frustrated figure on the touchline after Bertoncello's goal stood after a VAR review for a handball.
Footage showed the ball had made contact with Jets youngster Ben Gibson's right arm before Kosta Grozos collected to pull off a through ball for Bertoncello.
But Gibson wasn't penalised, having been held in a tussle with Macarthur's Tomi Uskok.
After Berntoncello levelled the scores deep into added time, Duke again showed his quality after halftime by superbly deflecting a cross from Callum Talbot for the match-winner.
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