A man who raped an employee inside a Park Slope beauty salon in 2006 has lost a bid to have his conviction overturned.

In an order released yesterday, Brooklyn federal Judge Allyne Ross rejected Marvin Winkfield’s argument that his conviction was flawed because his defense counsel had failed him.

The Brooklyn DA’s Office said Winkfield pretended to make a hair appointment before the attack, then once inside the salon — which was closed at the time — he dragged the woman into the bathroom and assaulted her.

He was convicted in a 2007 Brooklyn Supreme Court trial and sentenced to 35 years.

mmaddux@nypost.com