Purton, Moreira each ride four at Sha Tin

Zac Purton and Joao Moreira have put on a clinic at Sha Tin with four winners apiece on the 11-race program as they continue their premiership battle.

Defending champion Moreira went into Sunday's meeting three behind ex-pat Australian Purton and started with the first two winners.

Purton hit back and by the end of the day, his margin remained.

There are two meetings left in the Hong Kong season, Happy Valley on Wednesday and Sha Tin on Sunday.