Fierce Impact won the Makybe Diva Stakes but his victory was overshadowed by the return to racing of Russian Camelot, who he defeated narrowly.

The two horses, who are both being set for the Cox Plate, staged a stirring duel for the last 100 metres with Fierce Impact prevailing by a neck to win the Group One, 1600 metre race at Flemington.

It was a triumph for Warwick Farm trainer Matthew Smith who said it was a great result for his small stable and a great effort to defeat a serious racehorse such as Russian Camelot.

"Russian Camelot got the jump on us a bit but given that he's a horse that only does as much as he has to, it was better that he had something to chase," Smith said.

Smith said even though the margin was small, Fierce Impact tended to win in that style.

Smith said Mark Zahra rode Fierce Impact perfectly.

Zahra thought the seven-year-old was going to win easily but it took a long time to fight off a very good horse in Russian Camelot.

"He got in front of me but I hadn't fully hit my top yet," Zahra said.

"Ollie had got a bit of momentum going before the turn because we'd gone so slow. I had to sprint but he is good in a fight."

Fierce Impact again showed his love for mile races in Melbourne, the scene of his three Group One wins, but Saturday's was his first at weight-for-age.

The win gave Zahra his 17th Group One triumph and completed a double for him as he earlier took out the Bobbie Lewis Quality on Zoutori.

Smith said Fierce Impact would have his next run in the Caulfield Stake before the Cox Plate.

Danny O'Brien said Russian Camelot couldn't have done any more first-up and he couldn't be happier.

"He's been beaten a neck by a horse who is now a three-time Group One winner," O'Brien said.

"He had to race wide and without cover which really was the only option from that barrier and he avoided the interference when Gatting broke down."

O'Brien confirmed Russian Camelot would target the Cox Plate and he would run in the Underwood Stakes and Caulfield Stakes as his lead-in races.

"Ollie said that's a good path to the Cox Plate as racing him every two weeks will take the freshness out of him," O'Brien said.

Fierce Impact ($4 fav) defeated Russian Camelot ($4.60) by a short head with So Si Bon ($31) another 1-1/2 lengths away third.

The race was marred after 400 metres when Perth galloper Gatting, who won it the previous year, broke down in the near-side foreleg and had to be euthanised.