After bogeying 15 and 16 in windy conditions at St George's, Clark got up-and-down from about 50 feet from a semi-plugged lie on the downslope in a greenside bunker on the par-4 18th. He was seven-under after an even-par 70.

"Really had no chance," Clark said. "And I would love to say I was trying to do what I did, but I was trying to punt a little bit out to the right and somehow when I came into the ball it like plopped up to the left and landed in the rough and trickled down to four feet.

"It was definitely the best save I've had of the year. It was pretty awesome."

McIlroy (68) was tied with Matt Fitzpatrick (70), Alex Smalley (67), Keith Mitchell (67) and Jim Knous (67).

The former World No.1 had to wait three years to defend his 2019 title because of the COVID-19 pandemic that cancelled golf's fourth-oldest championship the last two years.

"Challenging," McIlroy said. "I think the only thing this golf course needs for it to feel a little more major like is just a bit of length. I think that's the only thing that's missing.

"The rough is very penal, the greens are tricky, the wind's up, it's drying out a little bit because of the wind. All of a sudden you've got a pretty testing golf course."