(AP Photo/Alastair Grant)

Wimbledon just lost half its audience – except in North Carolina.

Professional tennis is in one of those periods when it depends on relatively few superstars to keep the TV ratings high. Roger Federer and Rafael Nadal on the men’s side, Serena Williams on the women’s. When one of them goes out, there goes a chunk of the audience.

Federer, the 36-year-old Swiss superstar and top seed at Wimbledon, was expected to cruise into the finals against second-seeded Nadal. He had match point against South African Kevin Anderson after winning the first two sets, and everything was going according to plan.

Then, somehow, the eight-time Wimbledon champ did not close the deal and lost in five sets, the last a grueling 13-11 defeat to eighth-seeded Anderson. It’s only the third time in his career that he blew such a huge lead in a Grand Slam event.

Nadal nearly lost, as well, beating Argentina’s Juan Martin Del Porto in five sets after being down 2-1. The fact that Del Porto and Anderson were top 10 seeds shows how much tennis depends on its name-brand stars. Who has heard of them?

For North Carolinians, the saving grace is ninth-seeded John Isner from Greensboro, who will face Anderson in the semifinals. Isner is 6’10” and Anderson is 6’8” in what has to be the tallest semifinal in Grand Slam history.

Isner, who played college tennis at Georgia, burst onto the international scene in 2010 at Wimbledon when he was part of the longest match in tennis history – 11 hours and five minutes over three days. He won, beating a Frenchmen most of us never heard of.

Nadal and 12th-seeded Novak Djokovic will meet in the other semifinal, two popular players who will vie to be the heavy favorite no matter who advances to the championship match.  Nadal is 6’1” and Djokovic is 6’2”, so if it were one-on-one basketball, either of those guys would be in trouble.

But it’s not. It’s tennis, and unless you love to root for unknown underdogs, you may not have breakfast watching Wimbledon. The Federer-Nadal match we all expected, and most of us were rooting for, won’t happen.

Maybe Isner will come out of the clouds to win his first major title. That would be 6-foot-10 news, even outside of his home state.