The back nine at Royal Troon proved perilously difficult on the opening day with early clubhouse leader Patrick Reed labelling it ‘David versus Goliath.’
Problems around the turn saw promising early work undone for Willett and threatened to derail his hopes at the iconic Major championship.
But he recovered well to steady the ship and ensure no further damage was done ahead of the second round.
Masters champion Willett picked up three birdies in a four hole stretch from three to six as he made a strong early impression on Thursday morning.
But three straight bogeys in the first three holes of the back nine sent the 28-year-old tumbling back to level par.
As for many players, the road home became about one of survival and Willett did just that, carding pars on each of the final six holes to finish on level par.
Willett will be hoping afternoon play is more kind on Friday. Willett is out at 14.26pm with Fitzpatrick in one of the last groups to go at 3.10pm.
Birdies proved exceptionally hard to come by on the back nine due to the way Troon played on Thursday.
It was the American contingent that had coped best with the conditions by mid-afternoon.
Reed took the clubhouse lead on -5 after coming through the back nine with a rare pair of birdies. An eagle on three also aided his cause.
The top British finisher so far is Justin Rose, who will represent Team GB at the Olympics alongside Willett next month.
Rose finished three under par, again having picked up two birdies on the back nine.