Playing on a sponsor’s invite, Harrington carded a six-under-par 65, his lowest score of the year, to lie a shot off the lead shared by Haydn Porteous, Joost Luiten, and Nicolas Colsaerts at the Regnum Carya Resort.
Ian Poulter was a shot further back after a bogey-free 66 matched by fellow Englishman Eddie Pepperell, Kiradech Aphibarnrat, and Matthieu Pavon, with Lee Westwood and another Irishman, Paul Dunne, on four under.
Harrington, who was a vice-captain in 2014 and 2016, has not played in the Ryder Cup since 2010, but insists he could make the side next year in Paris by winning here or next week in Sun City.
“The reason I’m here is because if you win one of these two events, it puts you right there for the Ryder Cup,” the three-time major winner said. “It would kind of be in your hands if you got a good start like that.
“The last half dozen years I’ve been thinking it’s really tough to make this team, especially when you’re playing this mixed schedule here and over in the States. Now I might be resigned to the fact that it’s more about playing the right amount of tournaments and still needing to play and get lucky to make it.
“It’s tough when three or four of our top players eat up a lot of (the eight automatic) spots. It leaves very little room for everyone else.”
Harrington would be a likely vice-captain to European skipper Thomas Bjorn in 2018 if he does not look like qualifying and added: “Thomas has been very polite in not coming to me and talking to me like a vice-captain.
“He’s leading me to believe I’m still a player which is nice. In a few months time maybe that will start changing.”
After missing out on last year’s defeat at Hazeltine following four months out of action due to foot surgery, Poulter makes no secret of his desire to swap being a vice-captain for playing in Thomas Bjorn’s side in Paris.
“I would give literally my left arm to play,” Poulter said. “It’s a good golf course (Le Golf National). I’ve had success around that course. I’d love to be there.”
In the battle to win the Race to Dubai, Justin Rose recovered from a double bogey on the second to card a two-under-par 70, with Tommy Fleetwood returning a level-par 72.
Rose moved into contention for a second money list title with his victory in the WGC-HSBC Champions on Sunday, but remains more than a million points behind his fellow Englishman, with 985,000 points on offer to the winner in Antalya.