A week after a Group One double at Randwick, Te Akau Racing's trainer Jamie Richards and jockey Opie Bosson have racked up another at Ellerslie.

Avantage took out Saturday's Bonecrusher New Zealand Stakes (2000m) while two-year-old Cool Aza Beel dominated the Sistema Stakes (1200m) at the Auckland track.

Last Saturday, Te Akau Shark won the Chipping Norton Stakes and Probabeel the Surround in Sydney.

Three starts ago four-year-old Avantage won the Group One Telegraph (1200m) and went into Saturday off the back of another elite level win in the Haunui Farm Classic.

"She is just tough," Richards said.

"We've always spoken about her constitution and her strength.

"We're really lucky to have a stable full of quality horses and a wonderful team that looks after them.

"These are the types of horses that Dave (Ellis) goes to the sales to try and buy and the results are there to see."

Te Akau's Melody Belle won the Bonecrusher in 2019 and Richards believes Avantage can go on to emulate her stablemate.

"I don't think there is going to be much between these two mares in the coming years," he said.

Cool Aza Beel kept the roll going after being beaten last time out on a slow track.

"They didn't go that hard early on and he was pulling a little but once I got him out into the clear it was all over," Bosson said.

"He's a good colt and just a gun little racehorse.

"Last start he was just dipping and diving in the ground so I knew getting him back on to a good track, he would be hard to beat."

The Antony Fuller-trained Roger That, ridden by Samantha Collett, won the other Group One race at Ellerslie, the Auckland Cup (3200m).

Fuller prepares a small team at Tauranga and the Cup is by far his biggest win.

"It's just amazing," Fuller said.

"There is a young girl who works for us and she asked me this morning if I was excited.

"I said 'I think I'm bloody daft as I could have picked an easier race for the horse.'

"We were just hoping he would run well although we were confident he would stay."