Justine Henin and Maria Sharapova set up an explosive Australian Open quarter-final with crushing wins.
Second seed Fernando Gonzalez and defending champion Ivan Ljubicic both suffered quarter-final exits from the Vienna Open on Friday, leaving world number three Novak Djokovic as the tournament's only remaining seed.
Roger Federer once again conceded defeat to arch-rival Rafael Nadal when he and his fellow Swiss Stanislas Wawrinka lost to Nadal and Carlos Moya.
Guillermo Canas won his first tournament since a 15-month doping ban when he claimed the Brazil Open.
The Aussie ace feels his rapid slide down the world rankings could give Australia the advantage in the Davis Cup final against Spain.
Spaniards David Ferrer and Juan Carlos Ferrero also suffered first round shocks at the Valencia Open on Tuesday.
World number one Roger Federer breezed through to the Halle Open semi-finals with a 6-3, 6-4 win over Germany's Philipp Kohlschreiber.
Andy Roddick and Guillermo Coria raced into the fourth round with crushing victories.
World number one Roger Federer faces a potential third-round showdown with three-times winner Gustavo Kuerten in a tough opening week at the French Open.
The second seeded Federer will take on Juan Carlos Ferrero in the semi-finals of the Australian Open.
The American ace scored a dramatic victory over Spain's Juan Carlos Ferrero in the ATP Masters Cup.
Andy Roddick, Juan Carlos Ferrero and Roger Federer are in the running for the title at next week's Masters Cup.\n\n
The American stands a few points behind Juan Carlos Ferrero in the ATP entry ranking system.
Former British No 1 Tim Henman helped train the dogs for the December 6-9 tournament, which is held annually at London's Royal Albert Hall with plenty of the sport's veteran players taking to the court.
The defending champion battled back from 4-6, 1-4 down to set up a semi-final against unseeded Spaniard Nicolas Almagro, who upset 10th seed Juan Carlos Ferrero at the Barcelona Open.
The Aussie ace said he rallied after that to take the tie-break 7-0 and tie the Davis Cup match against Ferrero at 2-all.
He is the sixth American and just the 13th player in the history of the ATP rankings to finish the year at the top.
Agassi thrashed South Korean Lee Hyung-taik 6-1, 6-0, 6-0, while the Russian was beaten 6-0, 6-1 by Justine Henin-Hardenne of Belgium.
'It's pretty amazing to get the call from the Spanish king'
Delhi Dreams stormed into the final of the inaugural Champions Tennis League by overcoming a spirited Mumbai Tennis Masters by 27-21 in the best-of-five one-set clashes here at the Kalina University sports complex courts on Sunday night.
US Open champion Carlos Alcaraz has become the youngest world number one since the ATP rankings began in 1973.
Marcos Baghdatis subdued world number 16 Kevin Anderson in the crucial men's singles as Pune Marathas lifted the inaugural Champions Tennis League (CTL) trophy with a 27-23 victory over Delhi Dreams in the final on Wednesday.