Already the oldest winner in European Tour history, Spain's Miguel Angel Jimenez could improve his own record after taking a one-shot lead in the KLM Open at Kennemer Golf Club.
Jimenez, who broke his leg in a skiing accident last December shortly after winning the Hong Kong Open aged 48 and 318 days, fired eight birdies and two bogeys to card an opening six-under-par 64 in Zandvoort.
The last of those birdies on the 18th took the 49-year-old, who will be eligible for the Seniors Tour next season, out of a logjam at the top of the leaderboard, with compatriot Pablo Larrazabal, Ireland's Damien McGrane, England's David Howell, Paraguay's Fabrizio Zanotti, Scotland's Gary Orr and Australian Robert Allenby all five under.
Ryder Cup captain Paul McGinley carded a two-under-par 68, Shane Lowry hit one under, Simon Thornton finished on level par, while Padraig Harrington posted one over par.
Kevin Phelan and Peter Lawrie matched Harrington's one over, while David Higgins and Gareth Maybin posted two over.
Jimenez, who was in contention to become the oldest major winner in history in the Open at Muirfield before finishing 13th, said: "It was a little windy which made it more interesting but I am playing very well, very solid and a few birdies in the last few holes helps a lot.
"Holing a 40-metre pitch on the 16th for a birdie also helps."
Allenby and McGrane had reached six under but both three-putted the par-three 17th from a hollow short of the green, while Howell was inches away from winning a BMW M6 Gran Coupe worth €90,000 for a hole-in-one on the same hole.
"As it landed I looked behind me to see if there was a car as a prize and I couldn't see one," former Ryder Cup star Howell said.
"But then I saw one out of the corner of my eye and turned back to the green, but unfortunately it came up just short.
"A new BMW would've come in very handy with twins on the way at the end of the year. I think we might've upgraded to an X5, but it wasn't to be.
"I couldn't have come much closer, but you need a bit of luck for a hole in one, and the birdie was still very welcome all the same."
Howell, who is 57th on the current Race to Dubai with the top 60 qualifying for the end-of-season DP World Tour Championship, added: "I'm going to need a few more birdies, that's for sure. Home life's going to become very chaotic, but it'll also be a lot of fun and we're both really looking forward to it.
"My wife Emily's due in December, which is good timing as it coincides with the end of the season."
Orr, who has needed to visit the qualifying tour in each of the last two seasons to regain his card, is currently 234th in the money list after playing just seven events due to a recurring back injury.
"I'm delighted," the 45-year-old said of his round. "I played steadily but holed a lot of really good putts which kept the score ticking over.
"I've been struggling with my back again this year, it's been flaring up from time to time and it's a case of trying to play when I can and see how it goes.
"I probably shouldn't have played when I started, I should have given it a few more weeks and have been fighting it since, but I just take it a day at a time and see what happens. I've been working hard on my posture to try to stop irritating it and it has been better."
Irish Open winner Paul Casey hit two under, while home favourite Joost Luiten was a shot behind after a 69 and BMW PGA Championship winner Matteo Manassero carded a 70.
Belgium's Nicolas Colsaerts recovered from three over par after seven holes to get back to level par, but then ran up a triple-bogey seven on his final hole to card a 73.