Josh Kerr turned his audacious "Project 222" into reality under the lights of London Stadium, obliterating Hicham El Guerrouj's 27-year-old world mile record in front of a roaring home crowd. The 28-year-old Briton clocked 3:42.66, shaving nearly three seconds off his personal best and becoming the first athlete from his country to hold the historic mark since Steve Cram in 1985. Main Developments Kerr's winning time at the London Diamond League meeting beat El Guerrouj's previous record by 0.47 seconds, a margin that stunned many in the capacity crowd of 60,000. The 2023 world 1,500m champion had publicly targeted the Moroccan's mark since March, incorporating 222-second ice-bath recoveries into his training regimen as part of the project's psychological framework. "Going after records like that is not really anything about fitness, it's about wrapping your mind around that time," Kerr said after receiving a $50,000 bonus for the achievement. "I knew I had 3:42 in me. If I'm going to leave my mark on this sport as a British athlete... I have to be able to do those performances." Read also: Mbappe's Record and England's Bronze: A Chaotic World Cup Thriller Elsewhere at the meet, Keely Hodgkinson won her first outdoor race of the season in the women's 800m with a time of 1:56.21, saying she came only to win for the home crowd. American Brandon Miller surprised the men's 800m field with a personal best of 1:42.19, leaving Olympic champion Emmanuel Wanyonyi in fourth place after the Kenyan faded badly. Background El Guerrouj set his world mile record in 1999, the year Kerr was born, establishing a benchmark that stood for more than a quarter-century. The Moroccan's mark was considered one of the most durable in athletics, surviving challenges from multiple generations of middle-distance runners. Kerr becomes the seventh Briton ever to hold the mile record, a lineage that includes Cram, who last held it in 1985. The London Diamond League meeting also saw double Olympic pole vault champion Armand Duplantis withdraw after strapping was applied to his left thigh, following a first-time failure at 5.85m and a clearance at 5.95m. American Sam Kendricks took first place in his absence. World record holder Karsten Warholm ran the fastest 400m hurdles this year at 46.61, dominating the field without Brazilian rival Alison dos Santos. Why It Matters Kerr's record-breaking performance signals a shift in middle-distance dominance, returning the mile record to British hands for the first time in four decades. The feat validates the psychological approach of Project 222, which prioritized mental preparation alongside physical training, and could influence how elite athletes target seemingly unbreakable marks. The result also underscores the depth of British distance running, with Hodgkinson's strong season opener and Kerr's historic run both coming on home soil. What's Next With the European Championships scheduled for next month, Duplantis's injury withdrawal raises questions about his readiness for that competition. Kerr has not announced his next race but will carry the psychological weight of defending his world 1,500m title and the mile record simultaneously. The men's 800m picture has also shifted after Wanyonyi's surprising fade, having set a new 1,000m mark in Monaco just a week earlier, while Miller's breakthrough win introduces a new contender for global honors.