Complex sentence: It was also at this time that Melbourne Storm set a Rugby League World record attendance figure of 107,999 in the 1999 NRL Grand final, held at Stadium Australia they defeated the St George Illawarra Dragons, to win their first NRL premiership.
Split into simpler sentences: It was also at this time that Melbourne Storm set a Rugby League World record attendance figure of 107,999. This was during the 1999 NRL Grand final, held at Stadium Australia where they defeated the St George Illawarra Dragons, to win their first NRL premiership.