While leader Calum Hill carded his nine-under-par 63 on a fairly benign morning on the Fife coast, Henson’s equally impressive 67 was chiselled out in 30mph winds in the afternoon.
The 42-year-old, who plays mainly on the Asian Tour where he won the Philippines Open in 2012, shrugged off five successive missed cuts on the European Tour this season to card a first bogey-free effort on the circuit in three years.
Playing alongside German Marcel Siem, who was another of the players to cope best in the tougher conditions with a 70, Henson birdied the first and third before following an eagle at the par-5 sixth with a birdie at the next.
He then reeled off 11 straight pars, holing a 13-footer for par at the last to complete an outstanding display on the opening day of the £1.7 million event.
“It’s crazy to say that I may have left a few out there, but on the front nine I definitely had a couple that could have gone in,” Henson, who has been a professional for just under 20 years, told Sky Sports Golf afterwards.
“I kind of got a little break on the first hole. I hit it left and was in the heavy stuff. We were in between eight and nine and I hit this amazing fluff runner to 10 feet and made the putt.
“That kind of calmed me down. For me, 1, 2, 17 and 18 were going to be the tough holes today and, once I got past 1 and 2, I settled into the round and kept giving myself great opportunities.
“Coming here to St Andrews, the home of golf, it’s just a pleasure to be here and I feel very lucky and feel honoured to be here playing,
“I just had fun out there. I stuck to my gameplan. I played the shots the course gave me and I gave myself a lot of really good looks.”
Henson, who sits 252nd in this season’s Race to Dubai, laughed when he was asked how much experience he had of playing in windy conditions.
“That’s a good question because I’m a Southern Californian boy from Palm Springs and I’m more used to playing in a dome than here playing in 30mph winds. So not too much, but I love the challenge.
“I played a lot of professional golf and played the Dunhill one year (missing the 54-hole cut in 2019) so I’ve been accustomed to some of these conditions. No rain for me is nice.”
Referring to the forecast predicting it to be wet for the second circuit, he added: “I know tomorrow is going to be a big challenge, but I’m up for it,
“That’s what I’m here for. I’m here to get better and this is making me better and I’m just excited to be here.”