Course specialist Lee Slattery carded an opening 65 to lie a shot off the lead after the first round of the D+D Real Czech Masters.
Slattery, who finished second at Albatross Golf Resort in 2017 and fourth last year, fired an eagle and six birdies to finish seven under par alongside South Africa’s Erik van Rooyen.
Malaysia's Gavin Green held the lead on eight under after carding eight birdies in the first 12 holes and recovering from a bogey on the 13th with a birdie on the last.
Green also carded a 64 in the first round last year and went on to finish third behind Italy's Andrea Pavan, who began the defence of his title with a 68.
Paul Dunne leads the Irish challenge after carding a two-under 70, one ahead of Gavin Moynihan. Reunited with his golf clubs after a scare earlier in the week, Pádraig Harrington signed for a one-over 73.
Slattery is seeking a third European Tour title but was surprised to shoot such a good score after an indifferent start.
“I played the first four holes today so badly, I played them like a 15-handicapper,” Slattery told Sky Sports. “It was a bit of a surprise to play that well on the back nine after not playing great on the front nine.
“It was quite wet out there, it was kind of like playing target golf. This place can get quite fast and fiery and it has been over the years but today it was a different golf course.
“It played quite long but you just throw darts at the pins, I quite enjoyed it.”
Austria's Bernd Wiesberger, who missed seven months of last season after undergoing wrist surgery, is three shots off the lead as he chases a third victory in his last eight events.
“I try not to make whatever happens out here too dependent on how I feel off the golf course and in my life but I certainly appreciate what has happened the last couple of weeks,” Wiesberger said after his 67.
“I try to feed off it and not take it for granted either. Keep working and try to keep producing good scores and just enjoy myself out there.
“Even though I hit bad shots the frustration is maybe a little shorter than it used to be, so therefore it’s just a pleasure being out there and being in a position to play for these events again.”
Wiesberger qualified for the WGC-FedEx St Jude Invitational in the week after the British Open but decided to skip the $10 million event.
“I felt like I needed a couple of weeks off,” he added. “We had some great weeks, mentally tiring weeks, before the last break but we decided to come out and not make that break too long.”
SCOREBOARD
(British and Irish unless stated, par 72, (a) denotes amateur)
64 Gavin Green (Mal)
65 Erik Van Rooyen (Rsa), Lee Slattery
66 Joachim B. Hansen (Den), Hugo Leon (USA), Kristoffer Reitan (Nor), Callum Shinkwin, Kim Koivu (Fin), Edoardo Molinari (Ita)
67 Robert Karlsson (Swe), Jason Scrivener (Aus), Liam Johnston, Darren Fichardt (Rsa), Bernd Wiesberger (Aut), Thomas Pieters (Bel)
68 Kalle Samooja (Fin), Romain Wattel (Fra), Andrea Pavan (Ita), Bryce Easton (Rsa), Zander Lombard (Rsa), Soomin Lee (Kor)
69 Steven Brown, Jack Singh Brar, Oliver Fisher, Jacques Kruyswijk (Rsa), Hyo-won Park (Kor), Tapio Pulkkanen (Fin), Julian Suri (USA), Jeff Winther (Den), Robert Macintyre, David Howell, Haydn Porteous (Rsa), Pep Angles (Esp), Rikard Karlberg (Swe), Sam Horsfield, Chris Hanson, Ryan Evans, Wilco Nienaber (a) (Rsa)
70 Sihwan Kim (Kor), Mikko Korhonen (Fin), Dean Burmester (Rsa), Paul Dunne, Ales Korinek (Cze), Richie Ramsay, Matthew Nixon, Paul Waring, Matthew Southgate, Gonzalo Fernandez-Castano (Esp), Matthias Schwab (Aut), Brett Rumford (Aus), Victor Dubuisson (Fra), Jeunghun Wang (Kor), Jakub Bares (Cze), Jens Dantorp (Swe), Alexander Levy (Fra), Chris Lloyd, Ricardo Gouveia (Por), Berry Henson (USA), Christopher Sahlstrom (Swe), Thomas Bjorn (Den), John Catlin (USA), Bradley Dredge, Liam Robinson, JC Ritchie (Rsa), Nicolas Colsaerts (Bel), Ashley Chesters, Stephen Gallacher, Tom Murray, Jamie Donaldson, Lorenzo Gagli (Ita), Joel Girrbach (Swi)
71 Lasse Jensen (Den), Alexander Bjork (Swe), Renato Paratore (Ita), Daniel Gavins, Ivan Cantero Gutierrez (Esp), Kristian Krogh Johannessen (Nor), Marc Warren, Eduardo Ger Lao Riva (Esp), Louis De Jager (Rsa), Adri Arnaus (Esp), Mathiam Keyser (Rus), Anton Karlsson (Swe), Nick McCarthy, Stuart Manley, Gavin Moynihan, Stanislav Matus (Cze), Dimitrios Papadatos (Aus), Marcel Schneider (Ger), Nino Bertasio (Ita)
72 Ben Evans, David Law, Jonathan Thomson, Scott Jamieson, Aaron Rai, Duncan Stewart, Alejandro Canizares (Esp), Johannes Veerman (USA), Masahiro Kawamura (Jpn), Christofer Blomstrand (Swe), David Borda (Esp), Nick Cullen (Aus), Deyen Lawson (Aus), Philipp Mejow (Ger), Yi-Keun Chang (Kor), Justin Walters (Rsa), Pedro Oriol (Esp), Bernd Ritthammer (Ger)
73 Soren Kjeldsen (Den), Filippo Bergamaschi (Ita), Brandon Stone (Rsa), Adrien Saddier (Fra), Pavol Mach (Svk), Adam Bland (Aus), Ernie Els (Rsa), Eddie Pepperell, Lee Westwood, Filip Mruzek (Cze), Michal Pospisil (Cze), Aaron Leitmannstetter (Ger), Peter Valasek (Svk), George Coetzee (Rsa), Jan Cafourek (Cze), James Morrison, Gaganjeet Bhullar (Ind), Sam Brazel (Aus), Pádraig Harrington
74 Niklas Lemke (Swe), Espen Kofstad (Nor), David Horsey, Marcel Siem (Ger), (a) Jiri Zuska (Cze), Matteo Manassero (Ita), Paul Peterson (USA), (a) Simon null Zach (Cze), Raphael Jacquelin (Fra), Sebastian Soderberg (Swe), Lukas Tintera (Cze), Per Langfors (Swe), Scott Gregory
75 Grant Forrest, Petr Gal (Cze)
76 Matthieu Pavon (Fra), Tom Lewis, Max Orrin, Adrian Otaegui (Esp), Jin-ho Choi (Kor)
77 Jarin Todd (USA), Filip Raza (Svk), Max Schmitt (Ger), Josh Geary (Nzl)
78 Petr Hruby (Ger), Daniel Suchan (Cze), Austin Connelly (Can), Stefan Palenik (Svk)
79 Pedro Figueiredo (Por)
