The 53-year-old, who struck the opening tee shot at 6:32am, had an alarm call for 4:30am but after completing an opening 74, said: "I only went to sleep at 3:33.
"It was hard to get to sleep with the jet-lag. I played the US Senior Open last week (he finished 14th in Omaha) and had a hard time getting out of there.
"I had to fly to Chicago on Monday, then to London and then here. I got here Tuesday and played a practice round on Wednesday. I was pretty happy with how I hit the ball but I putted awful, the worst I have putted all year.
"I feel pretty good but come the middle of the afternoon I think I will crash. There will be a lot more sleep tonight [Thursday]."
Senior four-putted the first hole from short of the green but at least fared better than playing partner Lloyd Saltman, who hit two tee shots out of bounds and ran up a quadruple-bogey eight in a round of 79.