Thomas De Gendt and Nairo Quintana on top at Volta a Catalunya

Thomas De Gendt claimed stage four victory atop Port Aine ski station while Nairo Quintana secured the overall lead on a dramatic day in the Volta a Catalunya.

But Team Sky's Chris Froome again lost ground to the other leading General Classification contenders, as he came home eighth on the stage.

Dutch rider Pieter Weening made a bold bid for a lone breakaway success on a gruelling day that covered 172 kilometres and featured two special-category climbs.

Weening had been part of an earlier breakaway group, as was De Gendt, who fought his way back and overhauled the Dutchman around 2km from the line.

Weening eventually finished sixth but De Gendt was not for catching, the Lotto Soudal rider continuing to ride strongly in the closing stages and eventually crossing the line just over a minute clear.

The main action was in behind, where Quintana (Movistar) and Alberto Contador (Tinkoff) pulled away from the other main GC contenders on the final climb.

Contador began the day second overall and looked set to take the lead, only for Quintana to leave him behind late on and finish 15 seconds clear in second.

Froome crossed the line 37 seconds behind Quintana and is eighth overall, 46 seconds behind the Colombian race leader.

Friday's fifth stage is a 187-km ride from Rialp to Valls and the week-long race ends in Barcelona on Sunday.

Quintana currently holds a slender eight-second lead over Contador, with Richie Porte (BMC Racing) 17 seconds back, after edging out Contador for third place in Stage four.

Dan Martin (Etixx - Quick-Step) led the race overnight after his stage win on Wednesday but finished tenth on Thursday and has dropped into fourth.

"It was a great day, I felt much better than yesterday," said Quintana, who had lost a bit of time on Wednesday's summit finish.

"The main danger will be the Barcelona circuit (on Sunday). Contador is only eight seconds behind and the others are just a few seconds more behind. I'll have to watch out." 

Stage four result

1. Thomas De Gendt (Bel/Lotto Soudal) 4:52:04"
2. Nairo Quintana (Col/Movistar) +1:08
3. Richie Porte (Aus/BMC Racing) +1:23
4. Alberto Contador (Esp/Tinkoff) Same Time
5. Tejay Van Garderen (US/BMC Racing) +1:36
6. Pieter Weening (Net/Roompot - Oranje Peloton) ST
7. Ilnur Zakarin (Russia/Katusha) +1:41"    
8. Chris Froome (Gbr/Team Sky) +1:45"
9. Romain Bardet (Fra/AG2R) ST
10. Daniel Martin (Ire/Etixx - Quick-Step) ST

General Classification

1. Nairo Quintana (Col/Movistar) 19:01:43"
2. Alberto Contador (Esp/Tinkoff) +8"
3. Richie Porte (Aus/BMC Racing) +17"
4. Daniel Martin (Ire/Etixx - Quick-Step) +24"
5. Tejay Van Garderen (US/BMC Racing) +27"
6. Romain Bardet (Fra/AG2R) +32"
7. Ilnur Zakarin (Russia/Katusha) +42"
8. Chris Froome (Gbr/Team Sky) +46"
9. Hugh Carthy (Gbr/Caja Rural) +1:01"
10. Rigoberto Uran (Col/Cannondale) +1:16"