The Manxman, who won gold for Team GB in the team pursuit at the London 2012 Olympics, made his way round the TT course in 1hr 23m 48s to beat Boardman's time by just six seconds.
Former Tour de France yellow jersey wearer Boardman set the record way back in 1993, when Kennaugh was just four years old. The Sky rider got close to Boardman's time in 2012, taking the local record with a ride two-and-a-half minutes slower than the course record.
But Kennaugh returned this weekend to finally wrest the record from Boardman's grasp and pick up a £3,000 prize from local firm Shoprite, who have been offering an incentive for someone to break the record for the past few years.
Kennaugh, along with fellow British riders Luke Rowe and Ian Stannard, has renewed his contract with Team Sky for the 2016 season after a year which saw him win the British Championships and win a stage at the Criterium du Dauphiné.
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