Padraig Harrington took a three-shot lead into the back nine at the D+D Real Czech Masters as he looked for European Tour win number 16 in Prague.
The three-time Major Championship winner entered the day at Albatross Golf Resort in a share for the lead with Andrea Pavan but turned in 33 to get to 20 under and move three ahead of the Italian.
A 20 under par total would equal Thomas Pieters' record low total when claiming victory in 2015 and with Harrington eight under par on the back nine so far this week, the Irishman was eyeing a place in the history books as well as a first win since the 2016 Portugal Masters.
Malaysian Gavin Green and England's Tom Lewis were at 16 under, two clear of Pieters, Scotland's Scott Jamieson, Thai Phachara Khongwatmai and England's Lee Slattery.
Harrington found sand off the first tee and was forced to lay up but got up and down, holing from around 15 feet to lead on his own.
Pavan dropped a shot on the second and with Harrington saving par after a ragged tee-shot, the lead was two shots.
The Ryder Cup Vice Captain hit a bunker shot to two feet for another birdie on the sixth but Pavan made his first gain of the day from eight feet to stay within two.
Harrington then made the most of the par five ninth after laying up to stretch his advantage to three.
Lewis was proving the master of the par fives, making it four birdies out of four on the first, ninth, tenth and 12th and adding another gain on the sixth.
Green had started with seven pars in a row but an excellent approach into the eighth handed him a first gain of the day.
Lewis left himself some work to do off the tee on the par three 13th but made an excellent putt to briefly move within three of the lead and Green then took advantage of the ninth to join him at 16 under.
Belgian Pieters made an eagle-birdie start but could not progress any further in his first 13 holes, with Slattery having played 11, Khongwatmai ten, and Jamieson at the turn.
Fiji International presented by Fiji Airways champion Gaganjeet Bhullar held the lead in the clubhouse at 13 under after making an eagle and five birdies in a 66.
Australian Scott Hend had gone out with a marker and he completed a round of 73 in a remarkable one hour and 56 minutes.
