loss in Adelaide, where he was the seventh seed. He then made it to the second round of the Australian Open in January, only to retire against David Ferrer due to an injury. Del Potro returned to the circuit in March, winning his first match against Jesse Levine at the Sony Ericsson Open, before losing in the second round to López. Struggling with injuries, his ranking fell as low as no. 81 in April. "At the start of the year, I was playing good, but I had many injuries, many problems with my body, with my physique", said del Potro. "I changed my coach, changed my physical trainer, I changed everything." In May, del Potro had to retire again, this time in a first-round match against Andy Murray at the Rome Masters. During the second set, the Argentine allegedly made derogatory comments about Murray's mother which resulted in a complaint to the umpire. Del Potro's serve was subsequently broken three times in a row, and he suffered a back injury, which caused his retirement. In his second Grand Slam of the year, the French Open, he was eliminated in the second round by Simone Bolelli in four sets. In June, he reached the semifinals of the Ordina Open, losing to eventual winner and top seed David Ferrer in straight sets. For the second year in a row, he was knocked out of Wimbledon in the second round; he won his first-round clash with Pavel Šnobel in straight sets, but then lost to Stanislas Wawrinka. A successful summer followed for the Argentine. In July, del Potro and his team decided to remain in Europe to test his fitness. "We decided to play on clay courts for my back because if I start to play again on hard courts, maybe I will injure it again", he recalled. Del Potro won his first career ATP tour title at the Mercedes Cup in Stuttgart, defeating Gasquet in straight sets in the final. A week later, del Potro reached his second career ATP Tour final at the Austrian Open in Kitzbühel, where he beat local hope and sixth seed Melzer in less than an hour, to claim his second title in two weeks. Having competed in just two clay tournaments all of the 2007 season, he never thought he would win his first two titles on clay courts. In August, del Potro won his third