Mark Cavendish lagged behind the leading pack in stage four of the Tour of Britain as Dutchman Dylan Groenewegen edged home favourites Dan McLay and Ben Swift in a dramatic sprint finish to clinch victory in Builth Wells on Wednesday.

Expertly put in position by LottoNL team-mate Tom Leezer, Groenewegen burst clear and despite a spirited challenge by the British pair, held on to take victory at the line.

Belgian Julien Vermote (Etixx-QuickStep) placed fifth to retain the yellow jersey and his six-second lead over another Briton, Stephen Cummings, who was one of 57 to record the same time in the bunch sprint.

The riders were tested during the stage, at 217km the longest of the Tour, and a strung-out field cost Ongar's Cavendish any chance of coming into contention as he eventually finished over five minutes down on the leading pack.

An early four-man break had built a lead of five-and-a-half minutes by the halfway point of the stage, but it was gradually pulled back in a move led by Jack Bauer (Cannondale), which spread the field and accounted for Cavendish.

Further attacks were repelled until the group overhauled the early leaders with 25km to go, and it was Tony Martin who led under the flamme rouge as he looked to set up another win for his team-mate, race leader Vermote.

But ultimately it was Dutchman Groenewegen who held on for his second victory in Britain this year having also triumphed on the opening day of the Tour de Yorkshire.