From The European Tour
Olesen, who won a second European Tour title in Perth at the end of last season but has started just four times on the 2015 Race to Dubai, had been one of three co-leaders on six under par at the start of the day.
Having seen Swede Pelle Edberg set the clubhouse mark at eight under in the morning session, Olesen’s chances of reclaiming top spot appeared slim when he bogeyed the first and third.
But five birdies in the next six holes, culminating in efforts from 20 feet at the eighth and 12 feet at the ninth, allowed the 25 year old to turn in 32.
A bogey at the 13th briefly checked his progress, but Olesen birdied the 16th from five feet and saved par with a clutch ten footer at the 17th.
At nine under Olesen leads Sweden’s Edberg by a single shot at Heritage Golf Club, with England’s Matt Fitzpatrick and South Africans Thomas Aiken and Dean Burmester tied for third on seven under.
“On the front nine it was quite tricky but I kept it going out there and finished strongly with birdies on seven, eight and nine and then tried to keep fighting,” said Olesen.
“I’m enjoying being out there and I holed some nice putts. All in all it was a good day and I’m happy with three under.
“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. Mauritius is a beautiful country, so no matter what happens, I will still like it.
“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.
“I thought it would be the part that would be rusty, but it has actually been really good. I’m pleased at that it’s brilliant to be leading. It’s fun to be out there and be at the front again.”
Edberg, who came through his 14th visit to Qualifying School last November, and Aiken both shot rounds of 66.
“It’s not a bad start,” said Edberg, who has had 13 top-ten finishes on The European Tour but is yet to win. “I’ve played pretty solid and pretty nice both days.
“I’ve taken advantage of the par fives and the driveable par fours. I’ve been up there on pretty much every hole, putting for eagle, and those holes are the key this week.
“I’ve been hitting driver on every hole because I’ve been hitting it so good. Maybe I should take three wood on some holes, but not this week because I’m going for it.
“I hit it quite far and if I can get it in play, I’m only going to have a wedge in, so it doesn’t matter if I’m in the rough. I’m keeping it in play though and taking advantage of the par fives.”
Aiken also left his move until late, birdieing the sixth from 30 feet, the seventh from five feet, chipping in for par at the eighth and picking up a gain at the ninth from three feet.
“You’ve got to play good golf and I think this week is more about not making too many mistakes rather than making a lot of birdies,” said the three-time European Tour winner.
“So I’ll try and keep mistakes off the card and I hope I can keep doing that for the weekend.
“The putter behaved the last nine holes today, but other than that. I putted pretty averagely. I hope it continues to behave over the weekend.”
Former amateur star Fitzpatrick went round in 67, but admitted his round could have been even better but for a double bogey on the 17th – his eighth.
“To fight back after the double bogey and still finish four under is very pleasing,” said the 20 year old.
“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.
“It’s great being in Mauritius – I came here at the end of last year and it is great place. It’s been a great week so far, not only because I’m playing nicely, but we are looked after so well.”
There was some late drama on the cut line, which fell at two over par as Spain’s Javier Colomo made it through to the weekend with an albatross hole-in-one on the driveable ninth – his last.