Donald Trump may be king of the boardroom, but he's got a new rival for the title of TV's top tycoon, with the debut of Richard Branson's daredevil reality show on FOX, "The Rebel Billionaire."

Branson's show is described as "'The Apprentice' on high adrenaline," and the Virgin mogul even fired a shot at Trump, deploying a Donald look-alike. But now it's The Donald who's doing the dissing.

"I don't believe he's a billionaire," Trump told us. "I don't see how a person can be a billionaire when they own an airline. I would imagine much of his money is going into his airline to keep it afloat."

Before his show debuted, Trump's high-flying rival talked to "Extra" about his differences with The Donald. "I was just reading his ten rules for life," Branson said. "One of them was 'you don't shake hands with somebody because you might catch a cold.' I just don't agree with that philosophy."

Trump's response? "Richard Branson, your ratings speak very loudly and you just got fired."

And Thursday night on "The Apprentice," the apprentices go into the wedding business, and Trump's fiancé, Melania, plays a part in the biggest task reward yet.

Meanwhile, in related romantic developments, we got the exclusive as Raj, the bow-tied Romeo, went on a friendly date with Trump's assistant Robin.

"Robin, have a good time. Raj, you better behave yourself," were Trump's words of advice to the couple.

They went to Starbucks -- and Robin reminded Raj she has a boyfriend. Not exactly the most romantic rendezvous ever, but Raj remained enthusiastic: "Redeemed!" he crowed "I finally got Robin on a date."