J.T. Poston continued his terrific run of form on Friday to extend his lead to four strokes at the John Deere Classic, sitting at 15 under through 36 holes.

Coming off a second-place finish at the Travelers Championship last week, Poston shot Thursday's round of the day with a 62, and followed it up with a 65. Only six players had better rounds on Friday, with Maverick McNealy the sole 63.

Through two rounds, Poston now has 14 birdies, one bogey and one eagle.

In outright second place is Denny McCarthy, with rounds of 66 and 65, including going bogey-free on his second trip around the course to head into the weekend at 11 under.

The rest of the top-10 has strong international representation, with Austria's Matthias Schwab and Argentina's Emiliano Grillo part of a four-way tie for third place at 10 under, while Taiwan's C.T. Pan, England's Callum Taren and Canada's Michael Gligic are a further shot back in the log-jam at nine under.

South Africa's Christiaan Bezuidenhout and Canada's Adam Svensson are at eight under, America's Charles Howell III is at seven under, while India's Anirban Lahiri and Australia's Cam Davis highlight the large group at six under.

After narrowly missing out on a win at the Travelers Championship last weekend – losing due to a double-bogey on the 72nd hole – Sahith Theegala finished right on the cut-line at three under, highlighting the friendly scoring conditions.

John Huh missed out on the weekend's play by one stroke, Webb Simpson finished one under, and Cameron Champ missed the cut by three shots at even par.