In 2004 Zabaleta had defended his title in Båstad against childhood friend and French Open champion Gastón Gaudio 6–1 4–6 7–6(4). He made the semi finals of the Italian Open defeating Tim Henman and Nicolás Massú who were both in the top 15 at the time, before losing to Carlos Moyà. He also had quarter final appearances in Viña del Mar, Buenos Aires and Kitzbühel.Zabaleta started 2005 with quarter final appearances in Viña del Mar losing to Fernando González. After pushing the world number 1 Roger Federer to 3 sets in Miami Masters. In the quarter finals of the Monte Carlo Masters, Zabaleta was leading David Ferrer by a set and had to be carried off the court with a foot injury which kept him out for two months and he missed the French Open in the process. He came back to play in Båstad and lost in the quarter finals to Tomáš Berdych and made the semi finals in Kitzbühel and after a series of poor results, then he had surgery on his knee.Zabaleta continued to suffer knee problems in 2006 and finished outside the top 100 for the first time since 1997. He started 2007 by winning the La Serena Challenger defeating Juan-Pablo Brzezicki and was a finalist in Florianopolis losing to Óscar Hernández. After qualifying for the U.S. Men's Clay Court Championships, Zabaleta reached the final without losing a set and in the process defeated both finalists from 2006 Mardy Fish and Jürgen Melzer before losing to Croat Ivo Karlović. Zabaleta won the Bermuda Challenger and with this victory is back inside the top 100 in the ATP rankings.

Personal and miscellaneousIn 2004 he started his own show called Tenis Pro in which he takes the video camera with him to all the tournaments and highlights life on tour in a light hearted manner and along with Juan Ignacio Chela conduct various interviews with other players, along with other various skits.[edit] Singles titles (6)Legend (Singles)Grand Slam (0)Tennis Masters Cup (0)ATP Masters Series (0)ATP Tour (3)Challengers (3)No. Date Tournament Surface Opponent in the final Score1. April 22, 1996 Flag of the United States Birmingham Clay Flag of the United States Bill Behrens 6–4 6–42. November 2, 1998 Flag of Colombia Bogotá Clay Flag of Paraguay Ramon Delgado 6–4 6–43. July 7, 2003 Flag of Sweden Båstad Clay Flag of Ecuador Nicolas Lapentti 6–3 6–44. July 5, 2004 Flag of Sweden Båstad Clay Flag of Argentina Gaston Gaudio 6–1 4–6 7–65. January 15, 2007 Flag of Chile La Serena Clay Flag of Argentina Juan Pablo Brzezicki 6–2 6–46. April 16, 2007 Flag of Bermuda Bermuda Clay Flag of Canada Frank Dancevic 7–5 5–7 6–3[edit] Singles Finalist (5) * 1999: Hamburg Masters (lost to Marcelo Ríos) * 2002: St Pölten (lost to Marcelo Ríos) * 2002: Amsterdam (lost to Younes El Aynaoui) * 2004: Acapulco (lost to Agustín Calleri) * 2007: Houston (lost to Ivo Karlović)

1999年汉堡大师赛亚军