Marc Warren and Mikko Ilonen were the men to catch on day one of the British Masters supported by Sky Sports.
Scot Warren and Finn Ilonen both completed their opening rounds in 66 shots at The Grove to set the clubhouse target.
Starting at the tenth tee, Warren fired a birdie at his first hole before making another gain at the short 13th to get to two under.
A third birdie of the day at the 16th and back-to-back pars at the 17th and 18th saw Warren reach the turn in 33.
The 35 year old made a stunning start to his back nine, sending his approach at the long second to within a foot of the hole before rolling in for an eagle to jump to the top of the leaderboard.
Warren then sunk his 20-foot birdie putt at the third to move to six under and open up a two-shot lead at the summit.
After safely parring the next five holes, Warren dropped his only shot of the day at the ninth - his last - to fall back to five under.
Ilonen made a strong start to his first round, carding an eagle and a birdie on his way to reaching the turn in 32.
A birdie at the tenth was followed by a bogey at the next but Ilonen picked up shots at the 16th and 18th to finish on five under.
After his opening round, Ilonen said: "It was a perfect start. I played some of my best golf on the front nine.
"I sort of lost my rhythm a little bit there halfway through, but came back strongly and made two birdies at 16 and 18, which was nice."
Englishmen David Horsey, Lee Westwood, James Morrison and Richard Bland were one stroke behind the leading duo after producing opening rounds of 67.
Defending champion Matthew Fitzpatrick's first-round 70 saw him finish the day four shots adrift of Warren and Ilonen.
