Jordan Spieth has said that he has taken a "big step forward" in his preparation for The Open.
The American recorded a career-best 61 in the third round of the John Deere Classic and is in the lead going into the final round. He shot a seven-under 64 in round two.
"I made a big step forward today," Spieth told BBC Sport after round two.
"I wasn't feeling great after [Thursday]. But to come out today and shoot a solid round gives me a lot of confidence in my preparations for next week."
Spieth's chances of Open victory have been boosted by world number one Rory McIlroy's withdrawal due to injury.
