Complex sentence: On 21 November, Nakamura scored perhaps the most important goal of his career with a 30-yard free kick against Manchester United at Celtic Park in a crucial Champions League game, leading to Celtic qualifying for the Champions League knockout stage for the first time.
Split into simpler sentences: On 21 November, Nakamura scored perhaps the most important goal of his career to date with a 30-yard free-kick against Manchester United at Celtic Park in a crucial Champions League game. This goal led to Celtic qualifying for the Champions League knockout stage for the first time.