After Wimbledon in late June, Clijsters only lost one more match through early October. During this stretch, she won five titles including her third Stanford Classic and her fifth Luxembourg Open. She also built up a 22-match win streak and defeated Henin in the final of the Tier I Canadian Open in their only meeting of the year. Clijsters's most important title of the season was the US Open, her first Grand Slam singles title. As the fourth seed, she was not tested until the quarterfinals, when Venus Williams was two games away from defeating her at a set and a break up. Clijsters rebounded to win the match in three sets and then defeated the top seed and world No. 2 Sharapova in the semifinals, also in three sets. Despite her previous struggles in Grand Slam singles finals, she won the championship against No. 13 Mary Pierce with ease, only conceding four games. As the winner of the US Open Series, Clijsters received double the standard amount of prize money. Her $2.2 million prize was the largest in women's sports history at the time. Clijsters's last tournament of the year was the WTA Tour Championships. Although she had a chance to return to No. 1 if she outperformed the top-ranked Davenport, she only won one match and did not advance out of her round robin group. She finished the year ranked No. 2, having won a tour-best nine titles and all of her finals. She was named both the WTA Player of the Year and the WTA Comeback Player of the Year. Despite this success, Clijsters announced in August that she was planning to retire in 2007 because of her injury troubles.