In one of the most thrilling finales seen at the Tokyo Olympics so far, swimming rivals Katie Ledecky and Ariarne Titmus went stroke for stroke in the women's 400-meter freestyle final with the Australian just pipping her US rival. Titmus trailed Ledecky by almost a length heading into the halfway-mark turn, but managed to chase down the Olympic great to win her first-ever gold medal. Ledecky has been almost unrivalled in the pool since the 2012 Olympics and set the world record in this event five years ago on her route to winning four golds in Rio. Heading into the final, Ledecky held 23 of the 30 fastest times. But Titmus, known as "The Terminator" has slowly been catching up on the American. She finished in 3 minutes 56.69 seconds, the second-fastest in history, to just edge the battle on Monday morning. Now all eyes are set on the duo's next duel in the 200-meter freestyle final on Wednesday. "I tried to stay as composed as I could and use the speed that I have," Titmus said. "To pull it off in the backend against someone who has an amazing second half of her race, I'm really proud of that. I'm over the moon.'' Here is a roundup of the latest news and results from the Tokyo Olympics: Germany sealed its third medal at the Tokyo Olympics after Sideris Tasiadis won bronze in the men's canoe slalom. It is his second finish on the podium, with the 31-year-old winning silver in London 2012. Following a tight loss to Spain in their first group match, Germany's men's handball team recorded their first win against Argentina 33-25 to set themselves up for a place in the quarterfinals. Alexander Zverev defeated Daniel Elahi Galán of Colombia in straight sets 6-2, 6-2 in the second round of the men's tennis.
 History was made on Monday when Cheung Ka Long won the first-ever men's Olympic gold medal for Hong Kong China. The 24-year-old beat Italy's Daniele Garozzo in the final of the men's foil fencing, winning 15-11.   In the pool, swimming star Adam Peaty defended his gold medal in the 100-meter breaststroke, the first British swimmer to ever defend an Olympic title in the pool. The 26-year-old was the clear favorite and powered to the line in 57.37 seconds. Dutchman Arno Kamminga and Italy's Nicolo Martinenghi finished in silver and bronze, respectively. "It means the world to be me," Peaty told BBC Sport. "It is not about who is the best all year round, it is who is the best on the day. It is about who is adaptable and who wants it more." Japan's 13-year-old Momiji Nishiya has won the first-ever Olympic gold medal in women's skateboarding, taking out the street event at the Ariake Sports Park. Nishiya failed to land her first two tricks but a strong finish saw her total 15.26 points to beat out fellow teenagers Rayssa Leal of Brazil, 13, and compatriot Funa Nakayama, 16. It's Japan's second gold in skateboarding after Yuto Horigome won the men's street on Sunday. In the men's triathlon, Kristian Blummenfelt made a comeback victory to finish atop the podium - a first medal for Norway in the event. Blummenfelt trailed in fifth following the 1500-meter swim and 40-kilometer cycle but surged ahead during the 10-kilometer run to post a time of one hour, 45 minutes and four seconds. Britain's Alex Yee finished 11 seconds behind to take silver, while New Zealand's Hayden Wilde finished third. Elsewhere in the pool, Caeleb Dressel led Team USA to victory in the 4x100-meter men's relay as he kicked off his quest to win six gold medals. He's been touted as the successor to Michael Phelps. Dressel gave his team a formidable lead in the first leg, which they never relinquished - Blake Pieroni, Bowe Becker and Zach Apple combining for a total time of 3 minutes, 8.97 seconds. Italy and Australia followed on the podium. And Maggie MacNeil captured Canada's first gold medal at the pool with victory in the women's 100-meter butterfly. The reigning world champion edged China's Zhang Yufei to the finish line, while Australia's Emma McKeon took bronze. Great Britain's Tom Daley finally got his hands on a gold medal in the men's synchronized 10-meter platform. Daley and his teammate Matty Lee managed to overtake favorites China to claim victory in a tense and entertaining final. For 27-year-old Daley, it's reward for a long career in diving, at what is his fourth Olympic Games. Archery and surfing events have been postponed due to adverse weather conditions. Expected high wind and rain from a forecasted typhoon altered the archery plan, while poor swell forced a postponement in the surfing.