and Palermo. In 2004, Horna reached his career-high ranking of World No. 33, which was achieved on 30 August. Horna won the Bermuda Challenger over Martín Vassallo Argüello and made his first ATP final in Long Island losing to Lleyton Hewitt. Horna also made three semi finals at the Brasil Open, Houston and Munich. Horna finished inside the top 50 at the end of the year equalling the same feat by Jaime Yzaga. 2005–2006 2005 was not as successful for Horna and his singles ranking slipped to outside the top 50. He won his first doubles title with Argentine Martín García in Amersfoort and achieved his best ever performance at the French Open making the third round and defeating the seeded Tim Henman in the second round before losing to Victor Hănescu. Despite Horna winning his first ever ATP singles title defeating Juan Ignacio Chela of Argentina 7–6(5), 6–4 in Acapulco. After winning the title he said "Acapulco will stay in my heart. I've had an unbelievable experience here,". "It's like being at home". As well as reaching the third round of the Australian Open for the first time defeating Gaël Monfils before losing to Paul-Henri Mathieu and winning his second doubles title with Martín García in Palermo. Horna finished 2006 ranked outside the top 50 and had various injury problems relating to his arm and shoulder which affected his final end-of-year ranking. 2007 Horna had an unfortunate start to 2007 by losing his first round match at the Australian Open to doubles' specialist Max Mirnyi, after being frustrated by the umpire's refusal to eject an abusive heckler in the fifth set. His concentration was disturbed by the calls of "Well done, Beast" (Max Mirnyi's nickname) and "C'mon, roadkill". In February of that year he won his second ATP singles title, defeating Nicolás Massú for the only time in 7 matches 7–5, 6–3 in Viña del Mar, Chile, without losing a set in the tournament. In September, Horna and Iván Miranda took the Peruvian team of Davis Cup to the World Group for the first time by beating Belarus in Lima 4–1. 2008 While Horna has only made one semi final in 2008 in Acapulco, he has won 3 doubles titles in Auckland with Juan Mónaco, in Buenos Aires with Agustín Calleri and the 2008 French Open with the Uruguayan Pablo Cuevas. The 2008 Australian Open started an unusual sequence