Poulter wound up one shot ahead of former European world No. 1 Colin Montgomerie of Scotland.
Montgomerie had a chance to force a playoff on the last hole but left his birdie putt short from 15 feet. Playing partner Soren Hansen of Denmark birdied the last three holes to claim a share of third with Scot Stephen Gallacher and France's Gregory Havret.
Poulter, who had red streaks in his hair during his Celtic Manor Wales Open win earlier this year, arrived in Denmark sporting a bizarre style with blond and dark brown stripes.
But his golf was equally eye-catching as he carded four rounds in the 60s.
"It was nice to let the golf actually do all the work and stop people talking about the hair," said Poulter.
Selena Gomez drops F-bomb, walks off stage during Jingle Ball performance
Trader Joe's: Car crashes into Long Island store, injuring 11