London (AFP) - Austrian Bernd Wiesberger carded a stunning 10-under-par 61 to grab a share of the lead at the halfway stage of the Scottish Open on Friday, as Rory McIlroy moved into contention.
World number 396 Slattery and Van Rooyen both signed for their second successive rounds of 64.
But it was Wiesberger, having returned from a seven-month injury absence earlier this year, who stole the show, firing the lowest round of his European Tour career, rolling in 11 birdies.
"It's been tough the last year," he said. "Coming off injury, it's been hard but winning in Denmark a couple of weeks ago is a big boost to me.
"I am really enjoying my time out on the golf course again, maybe I take it not as seriously as I've done before and let it go and that really helped me, just feeding off rounds like this today."
World number three McIlroy sits six shots off the leaders after a second straight 67, as he bids to win the seventh national Open of his career.
McIlroy has won the US, British, Canadian, Australian, Irish and Hong Kong Opens.
"It's a cool thing to do," said the four-time major winner. "A lot of these Opens, Scottish Open, whatever, they are over a hundred years old, so to put your name on trophies like that is a pretty cool thing."
But the Northern Irishman's main focus will be on finding his best form before the start of the British Open next week at Royal Portrush, where he will play in a major on home soil for the first time.
"I'm slowly getting back to where I want to be," said McIlroy, who started the year ranked eighth.
"I'm very pleased with my year and there's still a little bit left to go, but I feel like my game's in good shape to finish the season off the right way."
"I feel comfortable, over really a lot of my game right now," said world number nine Thomas.
"I just need to keep continuing to do that, not only for the rest of the week but the rest of the season."
Matt Kuchar, who was tied for the lead after the first day, fell back with a 70, while Rickie Fowler's preparations for his latest tilt for a maiden major title suffered a blow as he missed the cut by a single shot on four-under.