Complex sentence: Then Sabatini then went on to beat Graf 11 in the next 21 matches they played between 1988 and 1992, with the Argentine going on a 5 match winning streak and Graf a four match winning streak.
Split into simpler sentences: Then Sabatini then went on to beat Graf in the next 21 matches they played. Sabatini won by 11 wins to 10, with the Argentine going on a 5 match winning streak and Graf a four match winning streak.