That's the good news for McGirt the bad news is that his joint leader is a man who enjoys a great record at the TPC Deere Run, Zach Johnson.
35 year old McGirt has finished runner-up at the Canadian Open in 2012 and 2013 so he has contended against even stronger fields than he will have to hold at bay this weekend but winning is a much tougher proposition.
McGirt stormed home over this closing nine holes today and even a bogey at the final hole could not put a dampener on what was a great round of golf although it did cost him the outright lead.
He will likely play second fiddle to relative local, Johnson, tomorrow but he relishes the situation.
"I love being in that position because you can go about your business and nobody really knows who you are.
"You can go to dinner and everybody kind of looks at you and goes, are you a golfer? Yeah. What's your name? William. You just leave it at that, and they walk away, and they're like, who was that guy.
"But no, I mean, it's great fun under the radar. You don't have as much attention on you. I'd say the expectations from a lot of people are lower so you can go out and have a chance to prove yourself.
In three previous starts in the event McGirt has missed two cuts and finished 60th so this week's effort to date represents a major turnaround.
Johnson becomes an even warmer favourite to win the title for the second occasion but it is his regular top finishes in the event that make remarkable reading. Johnson has not only won this event but he has been twice second and one third in recent years.
"I come in here expecting a fun week, said Johnson of his success over the TPC layout. "I come in here expecting myself to feel comfortable on this golf course. I don't have any expectation of coming here and playing great. I did at one time and not anymore. I just come here, I'm going to go play. I love these greens. Just going to go play.
"The attitude, that mindset is pretty simple, but it just seems to work. Bottom line is, though, we're talking about two days, so I've got two more days of golf. Just want to keep remaining patient, keep hitting solid shots. Hit a lot of really good drives today, and I think good things can happen."
Steven Bowditch has moved to a new level on the PGA Tour this year and once again finds himself in contention. Bowditch, who won in San Antonio earlier this year, added a second round of 67 to go with his opening 64 and is in a share of the lead just one behind the leading pair along with Johnson Wagner and Brian Harman.
Bowditch's last seven rounds in this event have been in the 60's so it is a layout he appears very comfortable with and if he was to go on with it this week it would be no surprise.
John Senden 25th and Greg Chalmers 35th are the only other Australians to make the cut.