Darren Clarke isn't getting ahead of himself after two good rounds at the Senior British Open, even after the Northern Irishman shot a three-under 67 at Sunningdale to hold a one-shot lead at halfway.

Clarke, who shot 65 on the opening day, won the British Open in 2011 at Royal St George's and could become just the fourth player to win both tournaments after keeping himself in pole on Friday.

"Certainly, I would love to have this trophy sitting behind the Claret Jug," said Clarke, who is at eight-under 132 in the final senior major of the year.

"But we're all long enough in the tooth to know that this is only two rounds."

Jerry Kelly (66) was a stroke back with defending champion Bernhard Langer (67).

The 63-year-old Langer, who eagled the first hole, won in 2019 at Royal Lytham & St Annes for his fourth victory in the event but the 2020 tournament was cancelled because of the coronavirus pandemic.

Paul Broadhurst eagled the first and was five-under on the day, two shots back overall with Ernie Els, a two-time British Open champion, who carded his second 67. Broadhurst won in 2016 and was runner-up in 2019.

Like Clarke, Els also has a chance to become the fourth player to win both events. The 51-year-old South African said he's "fighting hard" to stay close to Clarke, his playing partner.

"Darren is a great frontrunner, played really well today, so got a lot of work to do," Els said.