Playing their first match outside NSW, Genreau's clever 76th-minute finish after some great work by fellow youngster Jake Hollman gave the Bulls the edge on Tuesday.

English forward Matt Derbyshire then sealed the win in the 90th minute when he pounced on a loose ball and chipped Jamie Young from distance with the Roar pushing for an equaliser.

The defeat ends a four-game winning streak for the Roar who were unable to find a way past Adam Federici despite having eight shots on target and 19 attempts to Macarthur's eight.

In-form striker Dylan Wenzel-Halls, who had scored five goals in four games coming into the match, came closest for the home team when he hit the post shortly before Genreau's winner.

The 21-year-old had earlier been guilty of missing a gilt-edged chance when he was played in by a tremendous long pass from captain Mark Milligan, stabbing his effort wide.

His instinctive finish after Hollman had twisted and turned his way past Roar fullback Jack Hingert came against the run of play but coach Ante Milicic will not care.

The Bulls' boss had made seven changes to his starting lineup from the team which drew 2-2 against Western Sydney Wanderers last Saturday, keeping Derbyshire, Hollman and Spanish stars Benat Extebarria and Markel Susaeta on the substitutes' bench.

The move paid dividends with all four players coming on in the second half to great impact.

"You talk about the changes we've made but those boys have been excellent at training and they deserve an opportunity," Milicic said.

"To do well in this competition I'm a firm believer, you need to use your squad, that's what it's there for. So I'm delighted for the boys that came in, they really made a difference."

Brisbane, by contrast, stuck to the same starting XI which defeated Melbourne Victory 5-2 three days ago.

Roar coach Warren Moon admitted his team had lacked sharpness at times but also felt a late penalty shout for a foul on captain Tom Aldred could easily have gone the Roar's way.

"It looked a foul because it happens anywhere else on the pitch it's a foul and he was giving them all night, similar moments in the match," Moon said.

"But it's not and we move on and we're not going to make excuses for that ... we probably weren't at our sharpest tonight but we did enough to get something out of that game."

Macarthur, who moved to third with their third win of the season, face Adelaide United on Friday while Brisbane will look to bounce back when they host Newcastle at Redcliffe on Sunday.

Australian Associated Press