Article: Arsenal Ladies are the women's football club affiliated to Arsenal. Founded in 1987, they turned semi-professional in 2002 and are managed by Clare Wheatley. Arsenal Ladies are the most successful team in English women's football. In the 2008–09 season, they won all three major English trophies – the FA Women's Premier League, FA Women's Cup and FA Women's Premier League Cup, and, as of 2009, were the only English side to have won the UEFA Women's Cup, having done so in the 2006–07 season as part of a unique quadruple. The men's and women's clubs are formally separate entities but have quite close ties; Arsenal Ladies are entitled to play once a season at the Emirates Stadium, though they usually play their home matches at Boreham Wood.

Now answer this question: By 2009 what competition has Arsenal Ladies been the only ladies team to have won?
UEFA Women's Cup