The Englishman had missed his last two cuts and revealed after an opening 69 at Emirates Golf Club that he had been putting in the hard yards on the range over the last week.
Defending champion Bryson DeChambeau was among the later starters and he birdied three of his first four holes to also sit three behind Pepperell.
Pepperell was the man to break out of it, going on a birdie run around the turn after picking up shots on the tenth and 13th and bogeying the 15th.
He made gains on the 16th, 17th, first and second to lead by two, with Burmester the man leading the charge to catch him after birdies on the 12th, 13th, 16th and 18th.
Pepperell made his second bogey of the day on the sixth and when Burmester got up and down from the sand on the second, the duo were tied at the top.
Burmester also bogeyed the sixth to leave Pepperell in solo possession of the lead, and a big finish from Karlsson left him just one back in the clubhouse.
The Ryder Cup Vice Captain birdied the third, fifth and tenth and, after giving a shot back on the 15th, finished with two gains to get to seven under.
Wu was out in the very first group of the day and he recovered from a bogey on the third with birdies on the seventh, tenth, 17th and last.
Langasque made a hat-trick of birdies from the fourth and came home in level par in a 69.
Bezuidenhout was bogey free in a 66, with Perez dropping one shot as he too matched the lowest score of the week so far.
Heisele made four birdies in a row from the tenth in his 69.