Ryan Fox and Thorbjorn Olesen share the early at the Betfred British Masters, where defending champion Richard Bland and tournament host Danny Willett both made slow starts.
Fox birdied his final three holes to card a six-under 66 at the Belfry and match the total set by Olesen earlier in the day, who registered six birdies in his blemish-free start.
The pair hold a one-shot advantage over Scotland's Richie Ramsay, Germany's Hurly Long and China's Ashun Wu, while Bland and Willett are both seven off the pace after opening-round 73s.
Olesen, who was part of Europe's Ryder Cup success in 2018, is attempting to rebuild his career after he was cleared in December last year of sexually assaulting a woman on a British Airways flight back from a World Golf Championship event in July 2019.
"There's a lot of things I want to accomplish," said Olesen, who is without a win since 2018. "You have to stay in the present obviously but it's been a while since I've been in the winner's circle, and that's my main goal this year. Obviously I'm working hard on my swing, changed coach. It's starting to get a lot better and hopefully I can just build on some confidence with it."
Fox birdied two of his opening three holes and bounced back from a bogey at the sixth to pick up a shot at the ninth to reach the turn in 34, with the New Zealander then rolling in from 35 feet at the 12th and following back-to-back gains from the 16th with a long-range birdie at the par-four last.
"Hit it really solid," Fox said. "Maybe one tee shot on the second which looked a little dicey but hit a lot of wedge shots close and took advantage on a couple of the hard holes on 12 and 18."
A final-hole bogey dropped Edoardo Molinari two behind alongside Rasmus Hojgaard, Justin Walters and Brandon Stone, with 2014 Ryder Cup winner Jamie Donaldson and England's Jordan Smith both carding a three-under 69.
Lee Westwood bogeyed his final two holes to card a level-par 72 and Bland began his title defence after mixing two birdies and three bogeys, as Scotland's Robert MacIntyre stuttered to a two-over 74.
Watch the Betfred British Masters throughout the week live on Sky Sports. Live coverage continues Friday from 1.30pm on Sky Sports Golf.