Dan Martin finished in fourth place as Chris Froome seized control of the Criterium du Dauphiné on stage five on Friday.
Martin (Etixx-QuickStep) was in great form on the first of three mountain stages that complete the week-long race, attacking from the main group just three kilometres from the summit of the final climb of the 140km route to Vaujany.
The Irishman was quickly reeled in, however, with Team Sky rider Froome quickly countering with a surge that only Richie Porte (BMC) could match.
Froome proved too strong for his former team-mate as he crossed the line first to take the yellow jersey from Alberto Contador (Tinkoff).
Froome and Porte finished 19 seconds ahead of Adam Yates (Orica-GreenEdge) and Martin, with Contador (Tinkoff) a further two seconds back.
The Briton, who is gearing up for a bid to land a third Tour de France title, finished the stage with a seven-second lead over Australian Porte in the overall standings, with Contador now back in third, 27 seconds behind.
Martin's strong ride keeps him in the top five as he moved back ahead of team-mate Julian Alaphilippe into fourth place, 37 seconds off the lead.
Saturday's queen stage, a 141km ride to the Alpine resort of Meribel, will prove an even stiffer test of the climbers' legs and will likely decide the race winner.
