(CNN) -- Was this the real Rory McIlroy or an imposter? Given it's Halloween, it's a fair question.
The former world No. 1 hasn't won a title all year but led Shanghai's HSBC Champions -- the fourth and final World Golf Championships event of 2013 -- after the first round and then proclaimed it was his finest 18 holes this season.
It bodes well for the Northern Irishman, who is chasing a spot at the season-ending event on the European Tour, the World Tour Championship in Dubai. Perhaps beating Tiger Woods in an exhibition this week in China gave sixth-ranked McIlroy an added boost after a difficult year in which he failed to qualify for the PGA Tour's 30-man finale.
McIlroy said Thursday's seven-under-par 65 bettered his 64 at the Deutsche Bank Championship in Boston at the end of August.
"That was a good round of golf," the 24-year-old told reporters. "But this is probably better just because it was a little trickier conditions. There was a bit of breeze and you've got to play good golf to shoot seven under around this place.
"It's only one round of golf, but it's definitely the way I wanted, and needed, to start this week, keeping in mind that I obviously want to play myself into Dubai and try to pick up my first win of the season, as well.
"It's one of the best rounds I've played this season."
McIlroy struck eight birdies and only one bogey, on the 11th hole.
"It felt good to be out there and be in control of my golf ball," he said. "It's a great start, but it's only 18 holes.
"I've tried to stay patient the entire season, and I know that if I believe that I'm working on the right things -- and I am working on the right things -- then things will start to fall into place sooner or later."
McIlroy was two shots clear of Spain's Gonzalo Fernandez-Castano and Wales' Jamie Donaldson. U.S. Open champion Justin Rose and former Masters winner Bubba Watson were another shot back.
British Open champion Phil Mickelson was tied for 28th, six shots behind McIlroy.
Although he finished at one-under-par 71, his round was undone by a quadruple bogey on the eighth when he twice found the water, and he dropped another shot at the following hole -- his last, having started on the back nine.
Recently crowned FedEx Cup champion Henrik Stenson struggled, with the Swede finishing at two-over-par 74 to be tied for 57th in the 78-man field at Sheshan International.