The 47th-ranked Donaldson also showed how to master the course's narrow fairways and overcome the windy conditions. He had six birdies — including holing a bunker shot on his 12th — to go along with a bogey.
"Solid start, played some pretty good golf out there," said Donaldson, who was looking for his second European Tour victory. "Obviously 5 under is a great start. I played pretty good in most of the round but there were times when it wasn't quite on, we made some good up and downs. It was a matter of scoring well and keeping the momentum going."
The conditions were less kind to last year's winner Robert Rock, who finished with a 76. He was joined by Europe's new Ryder Cup captain Paul McGinley (76), who also is in danger of missing the cut.
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