At the 2004 Summer Olympics in Athens, Aresti extended his program by qualifying for two swimming events. He cleared FINA B-standard entry times of 51.45 (100 m freestyle) and 1:53.61 (200 m freestyle) from the Akropolis Grand Prix. In the 200 m freestyle, Aresti challenged seven other swimmers on the third heat, including Olympic veteran Aleksandar Malenko of Yugoslavia. He edged out Chinese Taipei's Chen Te-tung to take a sixth spot and forty-fourth overall by 0.24 of a second in 1:53.90. In his second event, 100 m freestyle, Aresti placed thirty-eighth on the morning's preliminaries. Swimming in heat four, Aresti blasted a Cypriot record of 51.10 to save a second spot over Papua New Guinea's Ryan Pini by 0.01 of a second.