Finals fever arrived in force at St John Oval on Saturday with Central reduced to 11 men at one stage and Macquarie now one win away from this year's Newcastle Rugby League decider.
In separate incidents either side of half-time, Randall Briggs was sent off for a high shot and Luke Walsh had 10 minutes in the sin bin as the Scorpions beat the Butcher Boys 36-18 in the qualifying semi.
Macquarie, who have injury concerns with both Kyle Kingston and Matt Moon, now visit minor premiers Maitland in next weekend's major semi.
Central, who also had Warren Schillings put on report late in the game, will tackle the winner of Sunday's elimination semi between Cessnock and Souths.
Macquarie were up 18-6 when Briggs was given his marching orders and Kingston was stretchered off late in the first half.
Walsh appeared to be reprimanded for back chat in the 45th minute.
Central rallied despite being down two troops, scoring consecutive tries to level at 18-all just after the hour mark.
However, the last quarter of the match belonged to Macquarie, who crossed three more times to seal the result.
Moon seemed to be clutching his shoulder in the closing stages.
Dean Morris nabbed a double for the Scorpions while Kerrod Holland kicked all six conversion attempts but missed penalty shots at either end of the encounter.
It was the first time Macquarie had defeated Central this season.
The Butcher Boys arrived unbeaten in their last 10 starts, featuring nine straight wins, and hadn't lost since May 28.
