Complex sentence: RK Gorenje Velenje won first match (27:24) and Koper won the other two (28:25 and 26:21) that meant RK Gorenje Velenje had to won the last 4th match with minimum of 5 goals in order to win the championship.
Split into simpler sentences: RK Gorenje Velenje won the first match (27--24) and Koper won the other two (28--25 and 26--21). That meant that Gorenje had to won the last fourth match with a minimum of 5 goals difference in order to win the championship.