Prague - Defending champion Thomas Pieters stormed into a tie for the lead at the halfway stage of the Czech Masters in Prague on Friday.
The Belgian is level with Denmark's Jeff Winther at the top of the leaderboard on 10 under par.
The 24-year-old Pieters went into the second day one shot behind overnight leader Ryan Evans, but he carded a bogey-free second successive round of 67.
Pieters claimed his maiden European Tour title in the Czech Republic last season and he continued to dominate the course at the Albatross Resort on Friday, with a double-bogey at the eighth hole in the opening round still his only blemish of the week.
The world number 61 needs to retain his title and win in Denmark next week if he is to remain in with a chance of qualifying automatically for Darren Clarke's European Ryder Cup team.
"It's always nice to go bogey-free and make some nice putts," Pieters, who finished fourth in the Rio Olympics competition last week, told the European Tour website.
"I'm hitting irons very well, my ball-striking has been very good the last few days. It feels controlled and stress-free golf.
"All I can do is do my best this week and we'll see where it brings me and then next week it's the same thing."
Winther, the world number 320, started his second round with an eagle at the par-five first, and a run of four birdies in five holes at the start of the inward nine helped him keep pace with Pieters and sign for a six-under-par 66.
Englishman Matthew Fitzpatrick, who is currently in possession of the last automatic European spot for the Ryder Cup matches that start at Hazeltine next month, settled for his second three-under-par effort of 69 in row to sit in a six-way tie for third.
Fitzpatrick's compatriot Andy Sullivan, the highest-ranked player in the field, struggled to a one-over-par 73 and missed the cut on plus four overall.
Former world number one Lee Westwood is eight shots off the pace on two under par.
Leading scores from the second round of the European Tour's Czech
Masters at the par-72 Albatross Golf Resort in Prague on Friday (GBR
& IRL unless stated):
134 - Thomas Pieters (BEL) 67-67, Jeff Winther (DEN) 68-66
- Tommy Fleetwood 70-68, Matthew Fitzpatrick 69-69, David Howell 70-68,
Robert Karlsson (SWE) 68-70, Steven Brown 69-69, Peter Hanson (SWE)
139 - Daniel Im (USA) 72-67, Richard McEvoy 72-67, Ryan Evans 66-73, Craig Lee 68-71, Marc Warren 71-68
140 - Oscar Stark (SWE) 71-69, Laurie Canter 70-70, Graeme Storm 68-72, Daniel Gaunt (AUS) 69-71, Florian Fritsch (GER) 69-71