Eddie Pepperell admitted he had exceeded expectations after playing himself into contention for the Dubai Duty Free Irish Open in his first event following a six-week injury lay-off.
A back problem had sidelined Pepperell since the US PGA Championship and forced him to miss the US Open at Pebble Beach, but the 28-year-old showed few signs of rust as he added a 67 to his opening 65 at Lahinch.
At eight under par Pepperell enjoyed a one-shot lead over fellow Englishman Lee Westwood, Mexico's Abraham Ancer and Spain's Jorge Campillo, with overnight leader Padraig Harrington slipping four shots adrift after struggling to a 73.
"I've surprised myself, I guess, to be in this position," said Pepperell, who won the Qatar Masters and British Masters last season.
"I don't feel like I've played great but I've certainly been quite steady and my short game has been great. To be in that position reflects that.
"I would be quite honestly disappointed if I didn't win, or certainly come close to winning, being in this position with my recent record in terms of my form over the last 12 to 18 months.
"I certainly feel very calm leading and if I don't get in my own way over the weekend I don't see why I can't win this tournament and I'm not afraid of winning it, so that's a nice feeling.
"I think in the past I would certainly have been a lot more nervy in this position but I feel relatively calm to be honest, so I'm looking forward to a good weekend ahead around a great course."
Westwood has played even fewer events than Pepperell this season, partly by choice and partly due to being ineligible for the Masters and US Open, but used all of his experience to recover from a poor start thanks to five birdies in eight holes from the seventh.
"It was a little tricky at the start. It wasn't very nice weather and a little bit drizzly and a lot of things to adapt to," the 46-year-old said. "I was a couple over after four holes but not really panicking.
"This golf course is tough to start off with and then gives you a few chances coming in so you've just got to be patient, and if somebody does get off to a fast start on the front nine then there's a really low one in store."
Harrington had proved that on Thursday by covering the front nine in 30 on his way to a brilliant 63, but was 10 shots worse off on Friday in an unhappy reminder of 12 months ago, when he followed a first-round 68 at Ballyliffin with a 78.
"You have to stick in there and I was a little better on the back nine so hopefully I have not done too much damage," the three-time major winner and 2020 Ryder Cup captain said.
"Four under par is still in it."