New signing Craig Goodwin pounced on a defensive error to score the game's only goal in the 31st minute.

The Lions heaped on the pressure, coming close twice when ex-Brisbane Roar striker Jean Carlos Solorzano hit the woodwork on two separate occasions.

"I think we are today the lucky winner," Kurz told Fox Sports.

"The Lions played very well, very aggressive with a lot of pressure of our defence line.

"We had the luck. For us it was important to reach the next round but the game wasn't our best."

The win sees the Reds into the last eight where they'll travel to Sydney to face APIA Leichhardt Tigers, who knocked out Melbourne Victory.

"It was our goal," he said. "We weren't happy with our performance but we reach our goal and in the end that's important."

The German refused to blame the side's intense pre-season for their sluggish display.

 

"No. In the pre-season it's normal," he said.

"We trained in the last couple of days one time less.

"It's more these games you win or lose with your mind. We weren't sharp enough today."