Getting ready to tee off on the first hole at the Medinah Country Club on Thursday, the 40-year-old American savoured the moment knowing that just two weeks earlier he was facing the most important surgery of his life.
'My biggest thought of the day was I was just so happy to be on the first tee,' said Mayfair, who was in the hunt at the 88th PGA Championship after shooting an opening round three-under 69 on Thursday.
'The sun was out and it was just a beautiful sight. I know where I was two weeks ago so I can't explain how great it was just to be here.'
Mayfair underwent surgery on August 3 to remove his right testicle after he discovered a strange lump while taking a shower.
'Two weeks ago if you had told me I was going to be here I would have never believed it,' said five-time PGA Tour winner Mayfair. 'I feel good. I think we caught it early and I am looking forward to playing golf this week.'
Mayfair said he appreciated the words of encouragement from the Chicago fans and that it was hard to keep his emotions in check Thursday.
'All these fans here in Chicago were just wonderful for me today and clapped and cheered me on,' Mayfair said. 'It was hard at times. I almost had tears in my eyes. I am thrilled to be here after what happened and the diagnosis.'
Mayfair said the lack of preparation time after the surgery affected him. He was six-under after the first 11 holes but stumbled down the stretch with three bogeys.
'I wasn't able to work out like I normally do before I come here,' Mayfair said. 'I took two weeks off before I was even diagnosed. So I haven't played for a month. Mentally and physically it wore me out today.'
The operation was a success, but Mayfair still has a decision to make regarding his ongoing treatment.
'The reason why I can play so soon is we caught it early. It didn't spread. I've always been a pretty fast healer.
'I do have a decision to make here in the next couple of months. Do I go home and have observations and tests done every two to three months for the next five years or do I go home and have two weeks of radiation?'
The latter would mean Mayfair would only have to be tested once or twice a year over a five-year period.