On a day affected by wind and heavy rain in Rio de Janeiro, Thiago Braz da Silva gave the home fans something to cheer about by winning gold in the pole vault. On the running track, David Rudisha defended his 800m title.
Rudisha wins 800m
Kenya's David Rudisha defended his Olympic title in the 800 meters with a dominant run in a time of 1 minute 42.15 seconds.
Rudisha, who won gold in a world record time four years ago in London, sat on the shoulder of compatriot Alfred Kipketer before accelerating with 300m to go.
Algeria's Taoufik Makhloufi, who won gold in the 1,500 meters at London 2012, and USA's Clayton Murphy challenged Rudisha on the home straight but the Kenyan held firm and finished in the fastest time in the world this year.
Da Silva claims pole vault gold for Brazil
Rio was in full party mood by the end of the night, when Brazilian underdog Thiago Braz Da Silva upset the odds to beat France's Renaud Lavillenie to win gold in the men's pole vault final.
Lavillenie, the reigning champion and world record holder, faultered at the very end struggling to get over the 6.08-meter mark which confirmed first place for the crowd favorite.
The result meant a silver medal for the Frenchman, while the USA's Sam Hendrick took bronze.
Miller dives over finish line
Allyson Felix missed out on becoming the first female athlete to win five Olympic gold medals in track and field, with Shaunae Miller diving over the finish line to edge out the reigning champion in the 400 meters with a time of 49.44.
Felix had been favourite to add to the golds won in Beijing and London, but she left herself too much to do on the home straight - and Miller of the Bahamas threw herself to victory.
The bronze went to Jamaica's Shericka Jackson in a time of 49.85.
Biles suffers surprise defeat
Sanne Wevers changed her gameplan at the last minute after American Simone Biles lost her footing on the beam, and it paid off when she became the first Dutch woman to win an individual gymnastics gold.
Biles had been favourite to win her fourth gold medal of the Rio Games but drew gasps as she lost her balance after a front somersault and had to grab the beam with both hands to stop herself falling.
Wevers had originally planned to go all out with her hardest routine, but made a late change of plan after watching Biles' error.
"That was actually the plan but after I saw her score I was like 'OK, maybe just be safe and be as high as possible on my D-score, but also really watch my execution'," she said.
Wlodarczyk in a league of her own
Poland's Anita Wlodarczyk smashed her own world record on her way to victory in the women's hammer throw - four years after being denied gold by Russian dope cheat Tatyana Lysenko.
Wlodarczyk, competing wearing the glove of her late friend and 2000 Olympics hammer champion Kamila Skolimowska, heaved a monumental 82.29 meters on her third attempt to crush the competition at Rio's sweltering Olympic Stadium.
"I think my record will be in my hands for another 20 years," said Wlodarczyk, who now owns the best 11 female hammer throws of all-time.
"London is history. We're in Rio now and I'm the best hammer thrower in the world," said Wlodarczyk.
Bahrain celebrate first gold
Kenyan-born Ruth Jebet won Bahrain's first ever Olympic gold when she claimed the women's 3,000 meter steeplechase with the second fastest time ever.
A world record was on the cards at the Olympic Stadium until the final few meters when Jebet slowed. She crossed in 8 minutes 59.75 seconds, less than a second off the world mark of Russia's Gulnara Galkina.
Jebet now holds two of the three fastest times ever over the barriers.
Tearful Viviani overcomes road cycling star Cavendish
Italy's Elia Viviani broke down in floods of tears in his parents' arms after overcoming a crash to win the Olympic cycling men's omnium gold ahead of Mark Cavendish on Monday.
Viviani was consistently strong over the two-day, six-event race and beat British road sprint star Cavendish into second, with 2012 gold medallist Lasse Norman Hansen of Denmark third.
"I'm happy. But for the points I lost in elimination, I could have been right up with Elia," said Cavendish, who was missing only one major honour from his palmares before this race - an Olympic medal.
"There was nothing I could do about that and give Viviani credit, he was strong,” said Cavendish. "I'm happy, I wanted gold but I got my medal, it's really nice.
"To have made it gold would have filled the collection but that's the way I am."
Russia win heavyweight gold amid controversy
Towering Russian Evgeny Tishchenko added Olympic gold to his world and European titles on Monday as he defeated Kazakhstan's Vassiliy Levit in controversial circumstances.
To loud jeers from the crowd, the judges gave the unanimous points decision to the Russian, leaving Levit looking bemused. The crowd continued to boo as the boxers took to the podium, with Levit getting a huge roar as he wiped away tears.
"I'm really upset about it," Tischenko said through an interpreter afterward. "I respect my opponent and the crowd. I cannot know why they booed."
Meanwhile, Levit couldn't make sense of the decision. "In my head I was thinking I won," Levit said. "The coaches were quite happy."