Spain's Javier Colomo carded the first albatross on a par four in European Tour history as Thorbjorn Olesen continued to enjoy a brilliant return from injury in the inaugural AfrAsia Bank Mauritius Open.
Colomo needed a birdie on his final hole of the day, the 322-yard ninth at Heritage Golf Club, to make the halfway cut, but did far better by holing his tee shot to complete a round of 69 in spectacular style.
"For the first time in my life I hit an unbelievable driver, very high with a little cut," Colomo said. "I tried to stop the ball on the green and the ball found the hole.
"I needed a birdie to make the cut, so a double eagle is just fantastic. I made a three-putt bogey on eight and I was two over and I needed birdie to make the cut. That's why I hit driver.
"We couldn't see (it go in). We heard some guys shouting but we couldn't believe that. We thought the ball was very close but when we were on the fairway, we couldn't see the ball on the green.
"And then one guy told me that the ball was in the hole. It was a perfect shot."
Colomo duly made the cut with two shots to spare on one under, eight shots behind halfway leader Olesen, who added a second round of 68 to his opening 65.
Olesen was one shot ahead of Sweden's Pelle Edberg, who carded a 66, with England's Matt Fitzpatrick and South African pair Thomas Aiken and Dean Burmester a shot further back on seven under.
Two-time European Tour winner Olesen discovered a tendon problem in his left hand over the winter but battled on for four events - missing the cut in the last three - before undergoing surgery after his last appearance in Malaysia at the start of February.
"I missed a couple of putts in the beginning today but then I holed some really nice putts and I feel like I have the pace of the greens," said Olesen, who was two over par after three holes but responded with five birdies in the next six.
"I'm really looking forward to the weekend. It's been a long break and then all of a sudden I'm up there in the lead, so it will be a lot of fun.
"I didn't have the biggest expectations this week but I knew I was swinging the club well and I've been practising hard the last couple of weeks. I was obviously hoping for something good, but I've been surprised at how good my short game has been this week."
Former US Amateur champion Fitzpatrick recovered from a double bogey on the 17th, his eighth hole of the day, to shoot 67 and said: "To fight back after the double bogey and still finish four under is very pleasing.
"It was steady and solid after that. I'm not too far off the lead. A two-shot swing can happen in a round or even on a hole here. We've only played two rounds and anything can happen."