Over the last two months, Fleetwood has won the Tour Championship for his first PGA Tour title — picking up $US10 million ($A15 million) as the FedEx Cup champion in the process — and been the top points scorer at the Ryder Cup retained by Team Europe.
Now the Englishman — up to No.5 in the world rankings — is leading the most prestigious golf tournament ever to be staged in India after making eight birdies in a bogey-free second round on Friday to jump to 12-under par for the week.
Fleetwood's last birdie — from eight feet at his last hole, the ninth — left him clear of former British Open champions Shane Lowry (69) and Brian Harman (65), who were tied for second place.
Fleetwood described the course at the tight, tree-lined Delhi Golf Club as a "unique challenge for all of us."
"I haven't hit more than a five-wood," he said.
"It's a test of patience ... if you hit it good off the tee you're going to have some short irons and wedges, and you feel like you've always got a chance to get it wrong. It's such a waiting game."
A further three shots back was Ben Griffin, a rookie for the Americans at the recent Ryder Cup, in a tie for seventh on eight under.
McIlroy, who again didn't put his driver in his bag, had back-to-back bogeys early in his back nine but responded by making birdie at four of his final six holes to shoot a second straight 69 to sit at six under, along with fellow European team member Viktor Hovland (67).
As No. 2-ranked McIlroy walked off No.18, he removed his cap and shook hands with Indian cricket great Sachin Tendulkar — a special guest for the tournament — at the back of the green.
"It was a strong finish, got myself sort of back in the tournament. I need a strong start tomorrow," McIlroy said.
Asked if he would be changing his strategy off the tee over the weekend to get more aggressive in a bid to chase down Fleetwood, McIlroy said: "I don't think so. I think if I'm struggling to hit fairways with my two-iron, I'm not going to hit it with my driver.
"Same strategy. Just have to hit it a little closer with my second shots and not miss as many putts."
Australian Jason Scrivener's second-round 69 was enough for him to scrape through to the weekend on two under, but his compatriot David Micheluzzi, having dropped seven shots over the first four holes on Friday, retired from the tournament.
