Bryson DeChambeau comfortably outscored tournament favourites Paul Casey and Patrick Reed to take the first-round lead at the Porsche European Open.
The American shot a six-under-par 66, which was three better than his English rival, while compatriot and Masters champion Reed was four strokes back courtesy of a birdie-birdie finish at the Green Eagle Golf Courses in Hamburg.
Three Frenchmen, Joel Stalter, Romain Wattel and Mike Lorenzo-Vera, and Germany's Benedict Staben, led the immediate challenge a shot further back.
“It’s great to start out with six under par. I think it’s one of my lowest rounds on the European Tour so I’m very pleased,” the world number 23, playing in only his sixth regular tournament on the European Tour outside of the Majors and WGC events, told europeantour.com.
“I haven’t been hitting it my best so I’m still working on my game and it’s starting to turn into some form.
“I’m missing in the right places and making some putts which is great. If you do that out here you’re going to be up there.”
Starting at the 10th he carded four birdies in his opening nine holes and – although he dropped a shot at the par-four third – he produced three further birdies in his last six holes, including a brilliant approach to the 517-yard last with his third from behind a tree.
World number 15 Casey briefly had a share of the lead at four under through nine holes, including an eagle on the par-five 18th, and a birdie at the last saw him bounce back from a double bogey at the short eighth.
That left him in a large group, including compatriot David Horsey and Scotland's David Drysdale, on three under.
Among those a shot better off were Welshman Bradley Dredge, and English pair Steven Brown and Oliver Fisher.
Reed, who appeared to be hampered by a knee injury, began with a birdie but struggled to find the fairway all afternoon finding a lot of the left rough – which cost him a shot on the par-five 11th.
Having fought to make pars on many holes he had a stroke of luck at the 17th when his birdie putt hit the back of the cup and dropped – otherwise it would have raced several feet past – and he followed that by picking up another shot at the last to close on two under.
Gavin Moynihan carded a five-over 77 in his first round, while Ruaidhrí McGee was two shots further back after an opening 79 that included two double bogeys.
SCOREBOARD
(British and Irish unless stated, par 72, (a) denotes amateur):
66 Bryson DeChambeau (USA)
67 Benedict Staben (Ger), Mike Lorenzo-Vera (Fra), Joel Stalter (Fra), Romain Wattel (Fra)
68 Steven Brown, Lasse Jensen (Den), Viktor Hovland (a) (Nor), Andrew Dodt (Aus), Oliver Fisher, Matthias Schwab (Aut), Scott Hend (Aus), Connor Syme, (a) Allen John (Ger), Bradley Dredge
69 Soren Kjeldsen (Den), Maximilian Kieffer (Ger), David Horsey, Jin-ho Choi (Kor), Hideto Tanihara (Jpn), David Drysdale, Philipp Mejow (Ger), David Lipsky (USA), Paul Casey, Nicolai Hojgaard (a) (Den), Alexander Levy (Fra)
70 Scott Jamieson, Henric Sturehed (Swe), Jose-Filipe Lima (Por), Peter Hanson (Swe), Laurie Canter, Jeff Winther (Den), Adrian Otaegui (Esp), Patrick Reed (USA), Steve Webster, Charl Schwartzel (Rsa), Richard McEvoy, Heinrich Arkenau (Ger), James Morrison, Stephen Gallacher, Sam Horsfield, Oliver Farr
71 Mikael Lundberg (Swe), Sebastian Heisele (Ger), Garrick Porteous, Matias Ca
lderon (Chi), Florian Fritsch (Ger), Kristian Krogh Johannessen (Nor), Tapio Pulkkanen (Fin), Max Schmitt (Ger), Harrison Endycott (Aus), Christiaan Bezuidenhout (Rsa), Clement Sordet (Fra), Callum Shinkwin, Christopher Mivis (Bel), Matthew, Baldwin, Zander Lombard (Rsa), Marcel Siem (Ger), Ryan Evans, Jordan Smith, Ross McGowan, Daisuke Kataoka (Jpn)
72 Nico Geyger (Chi), Birgir Hafthorsson (Isl), Carlos Pigem (Esp), Luca Cianchetti (Ita), Renato Paratore (Ita), Kim Koivu (Fin), Felipe Aguilar (Chi), Adrien Saddier (Fra), Rak hyun Cho (Kor), Alejandro Canizares (Esp), Thomas Detry (Bel), Nacho Elvira (Esp), Pontus Widegren (Swe), Mark Tullo (Chi), Christofer Blomstrand (Swe), Daniel Brooks, Mathew Perry (Nzl), Matthieu Pavon (Fra), Nicolas Colsaerts (Bel), Scott Fernandez (Esp), Julien Guerrier (Fra), Raphael Jacquelin (Fra), Liam, Johnston, Sebastien Gros (Fra), Chris Hanson, Georg Schultes (Ger), Justin Walters (Rsa), Jack Munro (Aus), Richard Sterne (Rsa)
73 Ricardo Gouveia (Por), Thomas Aiken (Rsa), Oliver Wilson, Eun shin Park (Kor), Marc Warren, Andreas Halvorsen (Nor), Thomas Bjorn (Den), Alexander Knappe (Ger), Edoardo Molinari (Ita), Gregory Havret (Fra), Richard Bland, Matthew Nixon, Jonas Kolbing (Ger), Maarten Lafeber (Ned), Ashley Chesters, Pep Angles (Esp), Nick Cullen (Aus), Tom Lewis, Oscar Serna (Mex), Jbe Kruger (Rsa), Jeunghun Wang (Kor)
74 Matteo Manassero (Ita), Jazz Janewattananond (Tha), Paul Howard, Chase Koepka (USA), Max Kramer (Aut), Minkyu Kim (Kor), Trevor Fisher Jnr (Rsa), Pat Perez (USA), Haydn Porteous (Rsa), Ajeetesh Sandhu (Ind), Simon Khan, Ash Turner, Harry Ellis (a), Gavin Hall (USA), Victor Perez (Fra), Gregory Bourdy (Fra), Nino Bertasio (Ita), Dennis Meyerrose (Ger)
75 Ben Evans, Lucas Bjerregaard (Den), Richie Ramsay, Paul Peterson (USA), Lucas Herbert (Aus), Brad Fritsch (Can), Luca Galliano (Swi), Lorenzo Gagli (Ita), Yusaku Miyazato (Jpn)
76 Fabian Becker (Ger), Jamie Donaldson, Pedro Oriol (Esp), Rasmus Hojgaard (a) (Den)
77 Gavin Moynihan, Niklas Adank (Ger), Eirik Tage Johansen (Nor)
78 Hurly Long (a) (Ger), Jonathan Thomson, Alex Fitzpatrick (a)
79 Kyle McClatchie (Rsa), Ruaidhri McGee
80 Mikko Ilonen (Fin), Aaron Rai, Marcel Schneider (Ger)
81 Chris Lloyd
82 Mathias Gronberg (Swe)