With Sydney's leading hoops unable to travel due to COVID-19 restrictions, Penza dominated Friday's showcase races.
Heading to the track for just three rides, Penza opened his account in the Tibbie Stakes (1400m) aboard Madam Legend for Les Bridge before adding the Newcastle Cup (2300m) on Great House and Cameron Handicap (1500m) on Ashman.
One of NSW's hardest working jockeys, Penza typically competes on the provincial and country circuits and has limited opportunities in black-type races.
He had ridden the winners of two Group races leading into the Newcastle Cup meeting and left with a career tally of five.
"It's a great thrill for myself," Penza said.
"I ride here every provincial meeting and do my best, but to come here on a great day like this and come out on top is very rewarding."
The placegetters indicated they are in for bright springs with Sky Lab finishing strongly despite being trapped wide throughout, while Duais was having her first start since claiming the Queensland Oaks.
Great House came from worse than midfield to give Waller his fourth Newcastle Cup (2300m) success and put himself in the frame for a start in the Metropolitan (2400m).
He firmed from $51 into $17 for the Group 1 staying contest after Friday's win.
The former European defeated Quick Thinker, who was held up in the straight and finished resolutely once clear to get within a neck of the winner, with the Waller-trained No Compromise another three-quarters of a length away third.