IZU, Japan—Laura Kenny became the most-decorated female Olympic cyclist as she rode to a fifth gold medal by partnering British team mate Katie Archibald to a commanding victory in the first-ever women’s madison in the Games on Friday. The British stamped their authority on a frantic race early on and their points advantage grew as main rivals the Netherlands were involved in a crash with 70 of the 120 laps remaining. Kenny and Archibald, taking turns around the 250 metre oval to hammer out a relentless pace, kept racking up points, winning 10 of the 12 sprints, and the only question was who would trail home in second place. Britain won with 78 points with Denmark duo Amalie Dideriksen and Julie Leth way back on 35 points. The Russian Olympic Committee’s Gulnaz Khatuntseva and Mariia Novolodskaia took the bronze medal with 26 points. Kenny, who was already Britain’s most successful …