American Quincy Hall produced a sensational finish to win Olympic 400 metres gold which denied Britain a first gold in the event in a century. World championship bronze medallist Hall trailed into the home stretch but then exploded and caught the leading Matthew Hudson-Smith right at the line for victory in a personal best 43.40 seconds. Hudson-Smith lowered his own European record to 43.44 seconds but it was only good enough for silver. He had been bidding to become the first British man to win the 400m since Eric Liddell in 1924, also in Paris. The bronze went to Zambia’s Muzala Samukonga in…