According to Official Guinness Records,
The fastest 4 km individual pursuit by a male cyclist is 4 minutes 7.251 seconds, achieved by Ashton Lambie (USA) in the preliminary round at the Pan-American Championships in Aguascalientes, Mexico, on 31 August 2018.A former gravel rider, Lambie’s world record caps a meteoric rise in only his second year of international track cycling competition. He took more than 3 seconds off Jack Bobridge’s record, which had stood since 2011.
For a complete list of 2018 records, please visit 2018 Guinness Records in Mexico.