Khan was world ranked 474th going into this week
England's Simon Khan refused to be downbeat after his second round at the USPGA Championship, despite three closing bogeys which cost him the lead.
The Londoner, 38, was level with eventual clubhouse leader Matt Kuchar on eight under before his round began to unravel on the 16th hole.
But Khan still finished on five under par, in a seven-way tie for third.
"On the whole it was really a good day," said Khan, winner of the European Tour's PGA Championship in May.
"My driver cracked this morning after one hole. I hit my tee shot on 18 when we restarted and the face cracked.
"So I pulled out my replacement driver, but I haven't hit it before and I struggled with it, to be honest.
"Then the wind this afternoon started really getting up and stayed pretty constant - the course really showed teeth.
"Saying that, you still got birdie opportunities and you just got to play the hard holes well."
Khan had to cram 29 holes - more than any other player in contention - into a day that began with another long fog delay, so mental fatigue may well have had something to do with his disappointing finish on the demanding Whistling Straits course.
It handed Kuchar a one-stroke overnight advantage over fellow American Nick Watney, with Khan having to settle for joint third alongside, among others, Northern Ireland's Rory McIlroy.
Khan learned he was playing in the final major of the year at the start of last week, although he was not in the PGA Championship field at Wentworth until just a few days before.
Last year's qualifying school winner stood 474th in the world entering that week but is now 107th - three places higher than Korean YE Yang was when he became the first player from Asia to win the USPGA last season.