Complex sentence: On 21 April 1997, while playing Mick Price in the first round of the World Championship, O'Sullivan made the fastest ever competitive maximum break in 5 minutes 20 seconds, an average of one shot every 8.8 seconds.
Split into simpler sentences: On 21 April 1997, while playing Mick Price in the first round of the World Championship, O'Sullivan made the fastest competitive maximum break. He completed the break in 5 minutes 20 seconds, an average of one shot every 8.8 seconds.