Rain suspended play on day two with just 68 golfers having completed their rounds and four groups not even making the first tee so it was a busy Saturday as the field played catch up at the Albatross Golf Resort.
Slattery was leading in the clubhouse when the suspension came but by the end of round two trailed by three as fellow Englishman Chris Hanson posted a 66 to get to 10-under.
Third round play got underway in the early afternoon and Hanson quickly extended his advantage with birdies at the first two holes, he and Slattery beginning to separate themselves from the field.
But a disastrous double bogey at the short par-4 4th derailed Hanson’s round and he would go on to post three more bogeys and another double on his way to a confidence sapping 75.
Slattery, meanwhile, remained in the same form that had seen him find 14 fairways and 17 greens in tough conditions Friday and his eventual 67 has him two clear at the top of the standings.
South Africa’s Haydn Porteous is outright second at 10-under and two back then it is a further two shots to Sweden’s Pontus Widegren.
Scrivener is part of an eight way tie for 11th after completing his second round in 2-under 70 then adding a 4-under 68 in the afternoon to be 5-under overall and seven off the pace.
It has been an indifferent year for the West Australian who has just one top 10 in a strokeplay event since the start of the year though was also fourth at the Perth Super Sixes.
Nick Cullen was the leading Australian when play was called Friday and at 2-under for the day through 16 had one of the better rounds going.
However, he dropped a shot at the last to finish in 71 then struggled to a 1-over 73 in the afternoon to slip to even par and well down the standings to T53.
Richard Green was the only other Australian to make the cut and at 1-under is T44.
Marcus Fraser, Brett Rumford, Nathan Holman, Wade Ormsby, Daniel Fox and Ryan McCarthy all missed the weekend’s play.