September 6, 2018
Serena Williams reacts after winning a point against Anastasija Sevastova, of Latvia, during the semifinals of the U.S. Open tennis tournament, Thursday, Sept. 6, 2018, in New York. (Seth Wenig/AP)
NEW YORK — Serena Williams was a bit shaky at the start of her U.S. Open semifinal. For all of six minutes.