The big Australian is playing in his second Masters -- he shot 72-79 to miss the cut in 2010 -- and leads for the first time in his career.
Leishman shot a fairly pedestrian 35 on the first nine but then went crazy on the second. He birdied No. 10, parred Nos. 11 and 12, then made four straight birdies on Nos. 13 through No. 16 before parring out for a phenomenal second-nine score of 31.
Here's a look at his scorecard:
He just missed shooting the lowest second nine in history for an international golfer. The record is 30. It has been done five times, most recently by Vijay Singh in 2002.
If the first-round lead holds, Leishman will not be in good company. Only Trevor Immelman (2008) and
Leishman was a 300-1 pick coming in; those odds have dropped a bit, to 25-1.
He was the 2009 PGA Tour rookie of the year. His highest career finish at a major is a T27 at the 2012 PGA Championship.