Complex sentence: The clubs progress was temporarily halted in 2002 when it came only sixth in the Regionalliga but it managed to win the league the year after and move up to the 2nd Bundesliga.
Split into simpler sentences: The clubs progress was temporarily halted in 2002 when it came only sixth in the Regionalliga. In the 2003 season, the team managed to win the league and move up to the 2nd Bundesliga.