He was tied 70 for the first round late yesterday, when a rain delay and the the resultant bad light forced early suspension of play.
As many as 14 golfers were yet to complete their opening round as one hour and 55 minutes of play was lost.
Lahiri seeking to make amends for The Open, where he missed the cut despite playing well in brutal weather conditions, started on the back nine and had a double bogey on par-4 14th.
He had three more birdies on his second nine, but bogeys on sixth and eighth meant he was only two-under.
Hudson Swafford, Brandon Hagy, Kevin Chappell, Matt Every and Ollie Schniederjans shared the lead after firing identical seven-under-par 65s at Glen Abbey Golf Club.
Both Hudson Swafford and Kevin Chappell are looking for their second wins in 2017, and for Chappell, a fine finish could result in a President's Cup birth.
Brandon Hagy and Ollie Schniederjans were both members of The 25 on the Web.Com Tour in 2016 and are looking for their first PGA Tour victories, while Matt Every has two Tour titles to his credit.
Smylie Kaufman fired a six-under 66 to sit tied for sixth.
Bubba Watson, whose wife, Angie is Canadian, shot six- under-par 66, his best-ever opening round at Glen Abbey Golf Club.
Disclaimer: No Business Standard Journalist was involved in creation of this content
