Fleetwood sits four shots behind Lowry after the Irishman carded a course-record 63 on Saturday.
Fleetwood himself hit a solid 66 and is Lowry’s closest challenger heading into Sunday at Royal Portrush.
Neither golfer has ever won a major with Fleetwood’s best finish being second at last year’s US Open.
And the Englishman knows he can’t worry about what his playing partner is doing in the final round of this year’s Open with the locals having provided leader Lowry with a vociferous backing on day three and the decibels expected only to go up on Sunday.
“It’s going to be a big atmosphere for sure,” Fleetwood told Sky Sports.
“I’m going to be in the last group and part of that, I’ve got to focus on me and just do my thing.
“Today was a smaller test of that because you could hear 15, 16, 17, I had my chances too on the back nine, but holes like 11, 14, but it seems because you hear the cheers, that he is holing everything.
“You’re having a great round, I’ve gone bogey free and shot five-under on Saturday, but it doesn’t feel as good as it should do because of the way Shane has played behind, he’s played amazing.
“It’s going to be a massive, massive challenge to focus on my own game and stay in the moment and stay in the present.
“It’s what it’s all about and I’m looking forward to it.”
Lowry also knows that there’s a long way to go but is letting himself dream.
He said: “It was one of the most incredible days of my life.
“Every time I had a putt I wanted to hoe it because I wanted to hear that roar. It was great.
“I’ll go to bed thinking about holding the Claret Jug, I’m only human.
“There is nowhere I would rather be than taking a four-shot lead into the final round of an Open in Ireland.
“It will be great whatever happens.”