On July 29, Johnson easily captured the 400 m Olympic title with an Olympic record time of 43.49 seconds, 0.92 seconds ahead of silver medalist Roger Black of Great Britain. At the 200 m final on August 1, Johnson ran the opening 100 metres in 10.12 seconds and finished the race in a world-record time of 19.32 seconds, breaking by more than three tenths of a second the previous record he had set in the U.S. Olympic Trials, on the same track one month earlier—the largest improvement ever on a 200 m world record. Some commentators compared the performance to Bob Beamon's record-shattering long jump at the 1968 Summer Olympics in Mexico City. During the race, Johnson strained a muscle in his leg, which prevented him from winning his third gold medal of the Olympics in the 4 × 400 m relay as Team USA went on to win the gold even without him.