Mother Nature can't slow down Jordan Spieth.
The winner of the first two majors this season, Spieth shot a career-best 10-under-par 61 Saturday to grab a two-shot lead at the John Deere Classic.
Spieth, who will try for his third straight major title next week at the British Open, was at 17-under 196 after the best round of the tournament since Steve Stricker shot a 60 five years ago at Silvis, Ill.
"With some good breaks and really good putting, a round like (Saturday) comes together," said Spieth.
Danny Lee is second after shooting a 62, followed by Shawn Stefani, Justin Thomas and Johnson Wagner at 14 under.
Spieth's round was highlighted by a pair of eagles, including a hole-out from 106 yards on No. 17. Spieth also made six birdies.
The round was suspended for close to three hours because of two weather-related delays.
Jerry Smith matched a tournament record with an 8-under-par 64 Saturday to take a three-shot lead after the second round of the Encompass Championship in Glenview, Ill.
Smith is at 14-under 130 as he seeks his first professional title of any kind. Mark Goodes was second, while Bart Bryant, Fred Funk and David Frost are among the group five strokes back.
Smith, who tied for third last week at the Seniors Swiss Open, was six under par for his first seven holes Saturday at North Shore Country Club, sinking an 11-foot eagle putt at the 579-yard, par-5 16th. He started on the back nine and shot 30.