Rider Don Wales smashed the previous world record of 80.792 mph with an astonishing 86.069 mph. The team, however, have said that they will hopefully return on Sunday to see if they can crack the 100 mph barrier.
The modified lawnmower achieved this feat of engineering still with the ability to cut grass, as the large crowds witnessed just moments before he set off.
Don is not the first member of his family, however, to break world speed records at Pendine. His grandfather Sir Malcom Campbell broke the world land speed record for cars in 1924, with a speed of 146.16 mph, just three years before embarking on a career in Formula 1.
American Bob Cleveland set the previous land speed record on a lawnmower at Bonneville Salt Flats, Utah.
Mr Cleveland was present yesterday after having flown in from the US to witness his British challengers cut the new record.