He also shot 40% from three-point range. He was also named the Greek League Most Improved Player that same season. Spanoulis was then drafted in the 2nd round, of the 2004 NBA draft, by the Dallas Mavericks, following this sudden emergence. He also made it onto the senior men's Greek national basketball team, at the 2004 Athens Summer Olympic Games. In the Greek Basket League 2004–05 season, his last season with Maroussi, Spanoulis averaged 15.9 points per game, and shot 37.8% from 3-point range, in 35 games played in the Greek Basket League competition. He then averaged 15.2 points per game, and shot 40.0% from 3-point range, in 12 games of play, in the European-wide 2nd-tier level EuroCup's 2004–05 season. For the year in total, Spanoulis averaged 15.7 points per game, and shot 38.3% from 3-point range, in 47 games played with Maroussi. He played in the 2005 Greek League All-Star Game, and was named to the Greek Basket League's Best Five Team. This was a breakthrough year for Vassilis, as he had averaged 11.1 points per game the previous season. He was considered to be one of the most improved players in Europe for the year. He helped to lead Maroussi to the 2nd place of the Greek Basket League, for the regular season. At the end of the year, Spanoulis was voted the European 6th Man of the Year, and Rookie of the Year in the EuroCup. He started being called, "The Greek Steve Nash", by some European fans, after this season. Following his outstanding season in 2004–05 with Maroussi, Spanoulis signed a 3-year contract worth €1.6 million euros net income, with EuroLeague powerhouse Panathinaikos Athens. Spanoulis and his agent, Miško Ražnatović, set the contract terms so that Spanoulis would have a buyout clause after just one year, and set the buyout amount at US $400,000. This was Spanoulis' first season playing at the highest European-wide professional club level. With Panathinaikos, in the Greek Basket League 2005–06 season, he won the both Greek Basket League championship and the Greek Cup. His team went 24–2 during the Greek Basket League regular season, and 8–0 during the Greek League playoffs, for an overall record of 32–2 in the national domestic league championship, and also went undefeated in the Greek Cup, at 5–0, for an overall record of 37–2 in Greek competitions.