Honours on the day, however, went to Ilnur Zakarin (Katusha), who overtook Thomas on the final bend to narrowly take the stage victory.
The 177km route from Nice to a summit finish at La Madone d’Utelle featured seven categorised climbs and began with Michael Matthews (Orica-GreenEdge) six seconds clear at the front of the GC. Thomas, placed sixth, was 23 seconds back.
At its largest, the day’s original breakaway consisted of seven riders and one chaser, and they pushed their lead to a maximum of 2-25. Tsgabu Grmay (Lampre-Merida), Cyril Gautier (Direct Energie), Niki Terpstra (Etixx-Quick Step), Gregory Rast (Trek-Segafredo), Antoine Duchesne (Direct Energie), Florian Vachon (Fortuneo–Vital Concept) and Evaldas Siskevicius (Delko Marseille Provence KTM) were ahead, with Andrew Talansky (Cannondale) chasing.
The peloton caught the break before the final climb, however, and then it was a test of strength to see who could create a decisive advantage in the race. Thomas was aided by team-mate Sergio Henao, allowing him to withstand attacks from first Contador and then Porte. He put the power down within sight of the finish and looked to have the stage sewn up, until Zakarin burst past on the final bend.
Tomorrow’s final stage sees an undulating 134km route that begins and ends in Nice. An ascent of race favourite Col d’Eze is followed by a 15km descent to the finish. Contador is best placed of Thomas’s rivals, 15s behind the leader.
Paris-Nice stage six, Nice to Madone d’Utelle (177km)
1. Ilnur Zakarin (Rus) Katusha at 4-45-11
2. Geraint Thomas (GBr) Team Sky, st
3. Alberto Contador (Esp) Tinkoff at 1s
4. Richie Porte (Aus) BMC Racing at 7s
5. Sergio Henao (Col) Team Sky at 10s
6. Simon Yates (GBr) Orica-GreenEdge at 20s
7. Rui Costa (Por) Lampre-Merida at 31s
8. Romain Bardet (Fra) AG2R La Mondiale at 31s
9. Jon Izaguirre (Esp) Movistar, st
10. Tony Gallopin (Fra) Lotto-Soudal, st
Overall standings after stage six
1. Geraint Thomas (GBr) Team Sky at 24-10-26
2. Alberto Contador (Esp) Tinkoff at 15s
3. Ilnur Zakarin (Rus) Katusha at 20s
4. Riche Porte (Aus) BMC Racing at 21s
5. Tom Dumoulin (Ned) Giant-Alpecin at 32s
6. Jon Izaguirre (Esp) Movistar at 37s
7. Sergio Henao (Col) Team Sky, st
8. Simon Yates (GBr) Team Sky at 44s
9. Tony Gallopin (Fra) Lotto-Soudal at 51s
10. Romain Bardet (Fra) AG2R La Mondiale at 1-00
