Spieth's 61 propels him to Deere lead

Jordan Spieth shot his best round of the week on Saturday at the John Deere Classic. It also happened to be the best round of his young, yet distinguished, career.

Spieth shot 10-under 61 in Round 3 at TPC Deere Run, usurping the lead at 17 under par, two clear of Greenbrier winner Danny Lee.

The Masters and U.S. Open winner ended in a flurry, going birdie-eagle-birdie to surge into control in search of a second Deere win on Sunday. The buns on the eagle sandwich were mid-range birdie putts, from 18 and 12 feet, respectively. In between was an eagle 3, holing out from 106 yards after a poor tee shot was clipped short by the trees guarding the left side of the 569-yard par 5.

"It was certainly maybe a couple of grooves low," said Spieth, who holed a somewhat thinned bunker shot here two years ago that eventually landed him his first PGA Tour win in a playoff. "I just seem to get some lucky breaks here at the John Deere Classic."

It was Spieth's second eagle on the day, backing up a round-starting eagle on the par-5 second with a second shot to 3 feet from 260 yards.

The 61 topples a pair of PGA Tour 62s for Spieth, including the second-round effort he turned in at Harbour Town earlier this year, as his best-ever pro round.

For Spieth, this result seems the mere progression of getting back into the swing of things. From the pro-am round on Wednesday, Spieth's first inside-the-ropes play since his U.S. Open win, to Saturday, his scores have improved.

"My first round was the pro-am, and that went rough," he said. "And then Thursday was a little rough, and then for whatever reason just started to really pick it back up."

Ryan Ballengee is a Yahoo Sports contributor. Find him on Facebook and Twitter.