The 2019 Race to Dubai was the first season in Fitzpatrick's European Tour career where he did not claim a win but he finished second four times and was in contention to claim the Harry Vardon Trophy right up until the final event of the campaign.
He already has a desert win on his CV and a victory this week at Abu Dhabi Golf Club would hand him a first Rolex Series triumph and make him the youngest Englishman to six wins.
His bogey free 67 moved him to nine under, a shot clear of China's Li Haotong.
After gains on the 13th, 15th and 17th, Fitzpatrick made a two putt birdie on the par five 18th to share the lead but he soon had Li for company.
The 24-year-old also took advantage of the 18th after making birdies on the 15th and 17th, and a five foot putt on the par five second meant he led alone.
Fitzpatrick broke a run of seven pars with an up-and-down at the eighth to share the lead again before Li found sand off the tee at the par three seventh for his only bogey of the day.
Westwood played a stunning tee shot on the par three fourth to add to birdies on the 11th, 13th and 15th, while Kitayama had four birdies and two bogeys in his 70.
Law bogeyed the second but then made five birdies in a row from the tenth in a 68, a score matched by Luiten with six birdies and a two bogeys.
Pieters combined five birdies with three bogeys to sit a shot ahead of Swede Sebastian Soderberg, who played the front nine in a brilliant 29 en route to a 64.