Complex sentence: Phelps' final home run might have been his most notable; it came before a sell-out crowd in 1990 on April 20, with two outs in the bottom of the ninth against the Mariners (Phelps was playing for Oakland).
Split into simpler sentences: Phelps' final home run might have been his most notable. It came on April 20,1990 with two outs in the bottom of the ninth against the Mariners (Phelps was playing for Oakland).