For the last 12 months Ana Ivanovic has been the great under-achiever of women's tennis. When she won the French Open last June the Serb appeared best placed to fill the void left by the retirement of Justine Henin, but after a year in which she has changed coaches, struggled with injury and suffered a series of embarrassing early losses in Grand Slam tournaments, she is down to No 12 in the world rankings.
Ivanovic came to Wimbledon having just ditched Craig Kardon only four months into his job as her new coach. When she had to save two match points before beating Lucie Hradecka, the world No 58, in last week's first round a prolonged stay did not seem likely, but Ivanovic has improved with each match and reached the last 16 with a morale-boosting straight-sets victory over Sam Stosur, who reached the semi-finals of the French Open.
Now comes the ultimate test. In today's fourth round Ivanovic meets Venus Williams, the five-times champion, who has swept through her first three matches with the ease of a vendor selling cut-price strawberries in the Wimbledon queue. Her victory over Carla Suraez Navarro on Saturday was her 17th in a row here.
Ivanovic won their last encounter, at last year's Australian Open, but Williams had recorded five successive victories before that, including one in straight sets in the Wimbledon semi-finals two years ago.
"I can take a lot from that match," Ivanovic said as she recalled that meeting here. "She likes to go for her first shot. She likes to dominate the points. I have to make a lot of returns. Obviously, it's going to be important for me to serve well because she has great first serves. If I can hold on to my serve and then put pressure on her that would be a key."
The first week here suggested that Venus and her sister Serena could be on course to meet in the final for the fourth time in seven years. Like her sister, Serena has yet to drop a set. Today she meets Daniela Hantuchova, who has already beaten Laura Robson, last year's junior champion, and Jie Zheng, a semi-finalist 12 months ago.
Amelie Mauresmo has never re-scaled the heights of 2006, when she won the title here, but after two mediocre years the Frenchwoman has rediscovered a degree of her past form. In her fourth-round match today, second on Centre Court, Mauresmo faces Dinara Safina, who would be a daunting prospect as world No 1 but for the fact that she has always struggled on grass. However, the Russian has made it to the second week here for the first time in seven attempts and has yet to drop a set.
Melanie Oudin, the 17-year-old American qualifier who beat Jelena Jankovic on Saturday, now faces Agnieszka Radwanska, the world No 14, while 19-year-old Sabine Lisicki, conqueror of Svetlana Kuznetsova, meets Caroline Wozniacki, the world No 9.