An electric opening 15-minutes laid the platform for a dominant 44-26 victory for the Mustangs over the defending Group 3 champions the Sharks.
The scoreboard flattered the Sharks in the end, as they scored three consolation tries after the Mustangs led 44-8 with 20-minutes remaining.
Macleay Valley raced out to an 18-0 lead after Chris Piper, captain Richie Roberts and Chris Carr crossed for tries.
The Mustangs were perfect throughout the opening quarter of an hour, as their discipline, attacking flair and strength in defence was on full display.
However, mistakes and penalties crept into the Mustangs game and they opened the door for Port Macquarie to answer.
Two tries to the Sharks saw the deficit reduced to 10-points before the home side regained momentum heading into the break.
Backrower Jesse Douglas barged his way over from close range before replacement winger Harold Thompson received a long ball from Josef Barber and got on the outside of the Sharks defence.
Thompson raced down the sideline and put a kick back in field to Owen Blair, who toed it ahead and regathered to extend the lead to 30-8 at half-time.
The Mustangs kept their foot on the throttle to start the second half as they scored with their first two possessions of the ball.
Roberts delivered a short ball to Barber who bumped off two defenders on his way to the line before Blair showcased his speed as he chased down a chip over the top, gathered the ball and dived over for his second.
Halfback Tyreece Sines then executed a pinpoint crossfield kick to Nate Welsh to extend the lead to 44-8.
The Mustangs, who were hampered by injuries and finished the match without any players on the bench, put the cue in the rack early and allowed the Sharks to score three late tries.
Mustangs coach Russell Lardner wasn't surprised by the result and claims the side can take their performance to another level.
"It's a big confidence builder, to earn a win like that against the defending champions," Lardner said.
"We believed we could come here and put a big performance together. There are some little things for us to work on and we will get even better."
The Mustangs' forward pack muscled up in attack and defence and Lardner gave them a massive wrap.
"I believe we have the best forward pack in the competition," he said.
"They were terrific today. They scored a couple of tries and were relentless in defence."
Lardner was proud of the young players in the side who stepped up into the first grade side.
"Kaine Parkinson made his first grade debut today and Harold Thompson, another young guy, came off the bench for us," Lardner said.
"They were both excellent and they will be knocking on the door for first grade spots all year."
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