Melbourne Victory's dead-ball king Gui Finkler broke Newcastle Jets' hearts with a late free-kick to seal a 1-0 win at AAMI Park on Saturday night.
The courageous Jets looked on course for a point before Finkler pounced from the edge of the area in the 85th minute with a scintillating blast to fire Victry to outright second on the A-League ladder - four points behind leader Perth Glory.
The ninth-placed Jets, who defended with courage and poise, remain in ninth place.
Muscat made a big call by planting club stalwarts Archie Thompson and Adrian Leijer on the bench in reaction to its derby defeat the previous weekend against Melbourne City.
And it was the home side which began brightly with the Jets under pressure from the kick-off and in-form Tunisian Fahid Ben Khalfallah skewed an early shot wide when well placed.
Khalfallah did hit the target with a long-range 20th minute free-kick but Jets keeper Ben Kennedy held firm.
And, buoyed by last weekend's first win of the season against Adelaide, the Jets forced their way into the contest - defending with venom and breaking out at pace when the chance arose.
Victory almost broke the deadlock in the 47th minute when Kosta Barbarouses arrived at the far post but fired over from an acute angle under intense pressure from Abdrew Hoole.
Khalfallah, Victory's most dangerous player, then cut inside and blasted off a low shot which Jennedy beat away as Victory turned up the tempo.
The Jets breathed a sigh of relief in the 56th minute when Khalfallah - who else? - rattled the crossbar with a venomous drive in the 56th minute.
Muscat introduced Thompson to great applause in the 71st minute as he sought to find the silver bullet that would crack opoen the Jets defence.
But it was Finkler who delivered when he stepped up to punish the Jets after James Virgili had fouled Besart Berisha on the edge of the area.
Scott Neville was denied an equaliser in the dying seconds by a fine save from Nathan Coe.