Hamburg - Bryson DeChambeau remained a shot clear at the halfway stage of the European Open in Hamburg on Friday, while his fellow American Patrick Reed stormed into contention with a second-round 66.
World No 23 DeChambeau looked in danger of slipping off the top of the leaderboard after a slow start, but a run of four birdies in his final seven holes saw him sign for a four-under-par 68 and a 10-under total.
The 24-year-old, who is one spot off the automatic qualification places for the US Ryder Cup team, is looking for his second title of the season after winning the Memorial Tournament last month.
"If I can strike the ball just a little bit better here and there then I'll play a little bit better and be really deep under par," said DeChambeau.
"I think the main thing I've got to focus on is executing the right shots and making good decisions with the wind."
Austrian Matthias Schwab fired a 67 to sit just one stroke adrift, alongside England's Richard McEvoy, who eagled the 18th hole to reach nine-under.
WATCH: Reed berates European Tour camera crew
Masters champion Reed was one of the earlier starters and went into the day off the back of consecutive birdies to finish his first round, and he rolled in seven birdies on Friday to get to eight-under for the tournament.
The 27-year-old said he thought a change of shirt colour helped him up his game.
"I just went back last night and talked to my coach on the phone and he said, 'don't overthink it, just get some rest'," said Reed.
"I needed some good luck going into today, so I thought I'd break out the green shirt and it seemed to work in the morning.
"On this golf course in the morning, with it being a little cooler, you're able to attack it, you feel fresh and ready to go and I was able to take advantage of it."
World No 15 Paul Casey also eagled the 18th to card a second straight three-under-par 69, as he bids to boost his hopes of qualifying for Thomas Bjorn's European side for the Ryder Cup in Paris in September.
Leading second-round scores from the European Tour's European Open in Hamburg, Germany on Friday (par 72/GBR & IRL unless stated):
134 - Bryson DeChambeau (USA) 66-68
135 - Richard McEvoy 70-65, Matthias Schwab (AUT) 68-67
136 - Patrick Reed (USA) 70-66, Romain Wattel (FRA) 67-69, David Drysdale 69-67
137 - Alexander Levy (FRA) 69-68, Bradley Dredge 68-69
138 - Philipp Mejow (GER) 69-69, Paul Casey 69-69, Renato Paratore (ITA) 72-66, Wang Jeung-hun (KOR) 73-65
139 - Oliver Fisher 68-71, Charl Schwartzel (RSA) 70-69, Scott Hend (AUS) 68-71, Hideto Tanihara (JPN) 69-70, Christofer Blomstrand (SWE) 72-67
140 - Scott Fernandez 72-68, Felipe Aguilar (CHI) 72-68, Sebastian Heisele (GER) 71-69, Connor Syme 68-72, Christopher Mivis (BEL) 71-69, Maximilian Kieffer (GER) 69-71, James Morrison 70-70, Lasse Jensen (DEN) 68-72