Hillingdon builders merchants Crescent Building Supplies won the NBG Challenge go-karting event, sponsored by Hunter Plastics and Marley Plumbing and Drainage.
Following a national series of heats covering the whole of the UK, Marley Plumbing and Drainage and Hunter Plastics hosted a national final at Daytona Racing in Milton Keynes.
The heats were held between members of the National Buying Group locally, the winners of the heat progressing to the national final.
Companies from as far apart as Inverurie to Hailsham took part and on the day the champions' crown was hotly contested.
The winners of the NBG Challenge were Crescent Building Supplies, Hillingdon (Middlesex); Cartmore, Fife (Scotland) and Huws Gray of Seacombe (Merseyside) were second and third respectively.
Allan Durning Executive Chairman of NBG said: "This has been a great series of events, allowing everyone to get to know each other better and foster good relationships with both Marley and Hunter."