Hong Kong-born Bennie, a former Perth Glory winger who helped Australia's Young Socceroos to U20 Asian Cup glory in February 2025, blasted home a right-footed shot in the 84th minute to help see off fellow promotion hopefuls Hull City 3-1.
It came after entering the contest just four minutes earlier at the MKM Stadium and Saturday's result moves QPR up to 13th in the standings on 47 points, seven behind the fifth-placed Tigers but only four adrift of the playoff spots.
"I'm just buzzing, it's been a long time coming ... it's the best feeling in the world," said 19-year-old Bennie.
"It just dropped to me on the edge of the box and I was just like, f*** it, why not hit it and it just went top corner."
But it was otherwise a quiet night for Socceroos attackers hoping to impress Tony Popovic ahead of next month's two World Cup warm-up matches in Australia against Cameroon and Curacao.
In-form Norwich City striker Mohamed Toure was subbed off on 71 minutes, unable to improve on his five goals in three games since joining the Canaries, in their 2-1 loss at home to Birmingham City.
Norwich were denied a penalty in the second half when Toure went down, while both Birmingham goals were close offside calls.
"Referees are human. They can't see everything and it's a shame they don't get the help this league deserves from VAR," Norwich manager Philippe Clement said.
"I think the Championship is one of the top eight leagues in Europe but it doesn't have VAR so sometimes you have conclusions like this."
Toure's fellow former Adelaide United young gun Nestory Irankunda was also replaced late in Watford's home game against Derby County, but his Hornets ran out 2-0 winners at Vicarage Road.
At The Den, Adrian Segecic came off the bench in the 70th minute as Portsmouth impressively defeated promotion-chasing Millwall 3-1.
Pompey made it back-to-back wins in the league for the first time this season after coming away from south London with all three points for the second time this week, lifting them six points clear of the relegation zone.
At the other end of the ladder, Riley McGree played the final half hour but could not help Middlesbrough find a breakthrough in a 0-0 home draw with second-last Oxford United.
The result left Boro in second, three points behind Coventry City after the Sky Blues' 2-0 win at West Bromwich Albion.
With PA.
