Hasi moved to KRC Genk in mid-1994, then to TSV 1860 München where he played only seven times during the 1997–98 season. He returned to KRC Genk establishing himself in starting lineup, winning the Belgian Title in 1998–99 season.
Hasi moved to RSC Anderlecht in May 2000 and, despite only playing 16 matches in his first season due to injury problems, helped the club retain their league title. He played 30 games the following year, including five in the UEFA Champions League to add to his five of the previous season.
Groin and knee problems restricted Hasi to eleven league appearances and four UEFA Cup games in 2002–03, however, but he returned to fitness to help Anderlecht win back the Belgian crown the following season.
In the 2004–05 season, he suffered torn ligaments in his left knee and was out for three months, when he came back he was limited to just 14 starts as Anderlecht relinquished the title.
Hasi moved to Lokeren during the 2005–06 season. On 11 June 2007, he signed a two-year contract with Cercle Brugge.
Hasi retired at the end of the 2007–08 season and became the assistant manager of his former club RSC Anderlecht. He signed a two-year contract at the club in 2008. On 10 March 2014 he replaced John van den Brom as head coach.