Germany's Martin Kaymer declared himself ready for battle this weekend after remaining firmly in contention for his second major title.
Bad weather is forecast at Royal St George's, but Kaymer feels equipped to cope after adding a 69 to his opening 68 for a halfway total of three under par.
The reigning US PGA champion, 26, said: "I think the first two rounds were fairly good and I'm happy with that.
"But if the weather comes in, if the rain comes in and the wind, then it's a battle. Then you need to fight, and then it becomes very difficult to keep that position.
"But I'm ready for it. I had a week off last week, so I'm prepared for some mental strength out there."
US Masters champion Charl Schwartzel also climbed into the reckoning with a 67 containing five birdies and two bogeys, but was surprised to be so high up on the leaderboard.
"A little bit," he admitted. "I had a good score out there, but I guess that's this golf course."
Meanwhile, 15 years after his victory at Royal Lytham, former Ryder Cup captain Tom Lehman struck a blow for both the fifty-somethings and the under-attack United States contingent at Royal St George's. For the first time since The Masters started in 1934, five successive majors have been won by non-Americans.
But 52-year-old Lehman is two under at the halfway stage in The Open after a superb 67.