The 33-year-old Argentine has been hinting at retirement for weeks, and he announced it on Monday on his Twitter account.

Fifth-seeded David Ferrer moved into the fourth round of the Australian Open with a 7-5, 6-2, 6-1 win over No. 27 Juan Ignacio Chela on Saturday.

Argentina's former US Open champion Juan Martin Del Potro will begin the 2012 season at the Sydney International next month, tournament organisers said on Friday.

German veteran Tommy Haas continued his comeback after hip surgery with an upset of fifth seed Juan Ignacio Chela in a 6-7 (3/7), 6-3, 7-6 (7/5) victory to reach the second round of the Austrian Open here on Tuesday.

Defending champion Juan Ignacio Chela of Argentina advanced to the quarterfinals of the Nastase Tiriac Trophy on Wednesday, defeating Florent Serra of France 6-1, 6-0.

Top-seeded Juan Ignacio Chela defeated Daniel Gimeno-Traver of Spain 6-4, 3-6, 6-3 on Wednesday to reach the quarterfinals of the Bet-at-Home Cup.

Argentina's Juan Ignacio Chela shattered Alejandro Falla's dreams of becoming the first Colombian man to reach a Grand Slam quarter-final with a five-set, last-16 French Open triumph on Monday.

Defending champions Argentina levelled the World Team Cup final 1-1 against Germany on Saturday in the singles after Juan Ignacio Chela beat Philipp Kohlschreiber in straight sets.

Second seed Roger Federer rolled over Juan Ignacio Chela of Argentina 6-0, 6-2 in the third round of the 4.5 million dollar ATP Masters 1000 event here on Tuesday.

Nicolas Almagro of Spain and Juan Ignacio Chela of Argentina advanced to the final of the Copa Claro clay-court tournament after each won two matches in a marathon day of tennis on Saturday.