London - Fernando Gaviria held his nerve to win the Tour of Britain's fourth stage after a tense duel with Team Sky's Elia Viviani on Wednesday.
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Quick-Step Floors rider Gaviria held off Viviani and Alexander Kristoff to take the 165-kilometre stage from Mansfield to Newark.
While Colombia's Gaviria won the daily honours, Viviani assumed the overall lead from Caleb Ewan.
Ewan is level on time with Viviani with four stages remaining, but the Orica-Scott star has lost the green jersey with the Italian boasting greater consistency.
Gaviria now sits third but trails by just six seconds, with Thursday's fifth stage a 16km time trial in Essex's Clacton-on-Sea.
"I've been coming back from an injury on my left leg. Every day has been going a little bit better. Today everything felt good," Gaviria said.
Meanwhile, Brent Bookwalter of the United States was forced out of the race after an ugly pile-up.
Bookwalter crashed into a car parked close to a tight corner and was forced to withdraw from the race, in an incident where several other riders also crashed.