Rio Olympic Games medal-winners on Day 4 : 21st gold for Phelps; Serena's shock exit
Michael Phelps' renewed quest for Olympic glory at the age of 31 has been nothing short of spectacular so far as he added two more golds to his tally as USA dominated day 4 once again. China's Deng Wei created a new world record in weightlifting, while Serena Williams faced a shock exit in singles.
In the Men's 200m Butterfly event, Michael Phelps won the gold with a timing of 1:53.36 in what turned out to be a thrilling race to the finish line between the American and Japan's Masato Sakai, who finished with a time of 1:53.40. Hungary's Tamas Kenderesi, who dominated in the heats, won the bronze.
Just an hour later, the 31-year-old was back in the pool, this time, to anchor the men's 4 x 200m Freestyle relay race. The USA team, which consisted of Conor Dwyer, Townley Haas, Ryan Lochte, and Phelps, dominated the race and finished three seconds ahead of Great Britain with a timing of 7:00.66—just two seconds behind the world record.
In weightlifting, China's Deng Wei won gold in the women's 63 kg category and decimated the world record in the process. The 23-year-old lifted 147 kg in the clean and jerk and 115 in the snatch to create  a new world record total of 262 kg in two lifts.
In tennis, World No.1 Serena Williams faced a shock exit in the third round. Ukraine's Elina Svitolina won the match 6-4, 6-3 to open up the race for the gold in the women's singles event. In another surprise result, French Open champion Garbine Muguruza lost to Puerto Rico's Monica Puig in a one-sided encounter 6-1, 6-1.
In men's singles, Rafael Nadal defeated Andreas Seppi 6-3, 6-3 in his second-round clash, while Andy Murray also cruised through to the next round with a 6-3, 6-1 win over the Argentine Juan Monaco.