His round featuring eight birdies put him ahead of compatriot Simon Khan with American Phil Mickelson and Thailand's Thongchai Jaidee among a group of seven tied for third on six under.
Parry, a former Tour champion at the 2010 Vivendi Cup in Paris who had to secure his return to the European Tour last November at its qualifying school, had missed the cut in seven of his first 10 events this season before finishing tied 28th at last month's US Open.
"I think from when I lost my (European Tour) card, I maybe panicked a bit coming into the last few events because you know you're struggling," the 26-year-old Parry the Tour website.
"Just make sure you do the right things constantly and you'll get the results.
"I've been playing better. I think the US Open was the catalyst for me to start playing better, making cuts. It's renowned for being the toughest event of the year... if you can compete on that, you know you can compete on any course."
Last year's winner, India's Jeev Milkha Singh, is on five under while South African Ernie Els, who will defend his Open crown next week, is at level par.
- Sports & Recreation
- Thongchai Jaidee
- Vivendi Cup