Lewis carded nine birdies and no bogeys in a flawless round at Diamond Country Club to lead by two shots from Dutchman Joost Luiten, with France’s Alexander Levy and English trio Graeme Storm, Simon Dyson and Richard McEvoy a shot further back. Leading Scot Callum Macaulay is in the group on four under.
Lewis burst on to the scene with an opening 65 at Royal St George’s in 2011, the lowest score by an amateur in Open Championship history, giving him a share of the lead. The 22-year-old went on to finish 30th and win the silver medal as leading amateur, before turning professional and winning the Portugal Masters in just his third event in the paid ranks.
However, Lewis struggled to reproduce that form in 2012, finishing 117th in the Race to Dubai with just one top-ten finish, and arrived in Austria on the back of six missed cuts in succession.
“This year has been tough but I’ve been close, I have shown some good stuff but it has not all come together,” said Lewis. “Today it did and hopefully three more rounds like that and I will be all right.”
Sixty five players took advantage of the soft conditions to break par, with veteran Miguel Angel Jimenez, 49, and Matthias Schwab, an Austrian amateur 31 years his junior, among those tied for seventh on five-under.
Jimenez, the oldest winner in European Tour history after his victory in the Hong Kong Open in November last year at the age of 48 years and 318 days, carded seven birdies and two bogeys.
Former tennis world No 1 Yevgeny Kafelnikov struggled to a 12-over-par 84.