McIlroy – the 2015 champion – was one of the favourites coming into the week but will now face an uphill battle to get out of Group Two after Kjeldsen produced a stunning performance.
“I felt good coming into today. And spoke to my caddie Alistair yesterday and he said, you know, go and shoot five under and see if it’s enough. Don’t worry about him. Obviously he’s pretty spectacular player so you don’t want to be watching too much! I knew that I had to play well to have any kind of a chance, therefore, I didn’t look too much at what Rory was doing. I played really, really well”, said Kjeldsen.
The Dane finished with four birdies to win a roller coaster of a contest where the lead changed hands five times.
That match was certainly among the best of the 32 encounters on what was an enthralling first day. Other highlights included Race to Dubai Number One Tommy Fleetwood birdieing the 18th to win one up over Zach Johnson, while Sergio Garcia and Shane Lowry halved an intriguing match on the 18th when Lowry made a bogey to allow the Spaniard to win the hole and halve the match.
Englishman Tyrrell Hatton continued his incredible run of form with a 2&1 win over Charles Howell III, while Belgium’s Thomas Pieters – the man who became Europe’s most successful Ryder Cup Rookie last year – continued to forge a fine match play reputation with a 3&2 win over Scott Piercy
At the other end of the scoring spectrum there were convincing victories for World Number One Dustin Johnson (5&3 over Webb Simpson); Phil Mickelson (5&3 over Si Woo Kim), Daniel Berger (7&5 over JB Holmes) and Charl Schwartzel (6&5 over Ben An).