Defending champion Purton started the day one behind his Brazilian rival – but a hat-trick from the first three races signalled his intent and the Australian added to his tally when taking two of the last three events on the card.
Purton got the ball rolling with Loriz, followed by Rich And Lucky and Bright Kid, before Reel Bizzy struck in race seven and Dances With Dragon came out on top in the nightcap.
That all propelled him to a lead of four over Moreira – 114 against 110, ahead of the engaging duel recommencing at Sha Tin on Sunday.
It was a first five-timer of the season for Purton, who said: “It’s been a bit of a grind, so hopefully I’ve now got a few more like this ahead of me.”
Purton was at his best on the Caspar Fownes-trained Dances With Dragon, keeping his cool on the top-weight as he searched for a clear run and then unleashed a decisive turn of foot to fend off the Moreira-ridden Enrichment.
Purton said: “It wasn’t as cool as it probably looked!
“It was a messy race with quite a bit going on. I had to get off the fence down the back because the horse in front couldn’t hold a spot and was going nowhere. I had to come out around on the corner and then back in and through them.
“We were lucky to get the run we got but the horse did a good job, he was up to the task.”
Loriz is trained by Ricky Yiu, who remains at the head of the trainers’ title race.
He said: “Zac is a strong rider and he rode the big horse really well – those big horses always run well for him – so I’m very pleased.”
Purton had immediately followed his win in the opener with a perfectly-judged front-running triumph on the Peter Ho-trained Rich And Lucky. That victory took the trainer to 12 for the term.
Bright Kid defied odds-on favourite Yee Cheong Pegasus to take race three for the Chris So yard, while Purton made it four and counting when the Danny Shum-trained Reel Bizzy dug in to repel rivals.
Select any odd to add a bet