Who was the defending champion when Martina Navratilova won her first Wimbledon singles title?

Sarah Virginia Wade (born 10 July 1945) is a former professional tennis player from Great Britain. She won three Grand Slam singles championships and four Grand Slam doubles championships, and is the only British woman in history to have won titles at all four Grand Slam tournaments. She was ranked as high as No. 2 in the world in singles, and No. 1 in the world in doubles.

Three times a Grand Slam singles champion, her most famous success was winning Wimbledon on 1 July 1977, the tournament's centenary year, and the year of the Silver Jubilee of Queen Elizabeth II (the Queen attended Wimbledon for the first time since 1962 to watch the final). Wade was the last British tennis player to have won a Grand Slam singles tournament until Andy Murray won the US Open in 2012. She remains the most recent British woman to have won a Grand Slam singles title. After retiring from competitive tennis, she coached for four years and has also worked as a tennis commentator and game analyst for the BBC and Eurosport.

Wade was the defending Wimbledon champion when Martina Navratilova won her first major singles title at Wimbledon in 1978, where she defeated Chris Evert in three sets in the final and captured the world No. 1 ranking for the first time on the Women's Tennis Association (WTA) computer, a position she held until Evert took it back in January 1979.