Chris Froome put in a brave attack on the final climb but was forced to hold station as stage 19 of the Vuelta a Espana ended in stalemate.
The Brit attacked towards the summit of the second category Alto El Vivero but was unable to escape the attentions of race leader Juan Jose Cobo (Geox) as the two riders broke clear.
With a flat 14-kilometre run back to the finish in Bilbao it proved impossible for Froome to open out a gap over his rival meaning Cobo still holds a 13-second lead at the top of the standings with two stages remaining.
Bradley Wiggins paced Froome up the final climb and remained in close attendance as things came back together at the finish with the duo maintaining second and third positions overall.
Local rider Igor Anton rode to a popular victory on the day as the race made its long-awaited return to the Basque Country.
The Spaniard took a convincing win for the local Euskaltel-Euskadi squad after attacking his breakaway counterparts on the decisive final climb to set up a solo run into Bilbao.
Marzio Bruseghin (Movistar) was forced to settle for second on the day, 41 seconds back after failing to close down Anton on the run to the finish while Dominik Nerz (Liquigas) edged third from a chasing group.
Team Sky did their best to keep the pace high and pile pressure onto the red jersey-holder in the closing kilometres in front of a passionate Basque crowd as the race returned to the region for the first time since 1978.
The squad hit the front on the approach to the first of two ascents of the Vivero, Ian Stannard putting in a big turn before allowing Thomas Löfkvist to set the tempo over the climb.
The effort saw the gap to the day’s breakaway quartet fall rapidly after Bruseghin (Movistar), Alexandr Dyachenko (Astana), Anton and Gorka Verdugo (Euskaltel) had worked together well to amass an advantage of six minutes.
Löfkvist continued his heroic turn on the front to lead the field onto the finishing circuit with Wiggins and Froome and close attendance as thick crowds lined the roadside.
The escapees held a gap of 1:46 at the finish area in Bilbao where the damage done by the effort became apparent as a much-depleted peloton crossed the line for the penultimate time.
Joaquim Rodriguez (Katusha) was the first to attack as the group hit the foot of the climb for the final time while up ahead the break fractured completely with Anton going it alone up the steep ramps.
Wiggins then took up the reins at the front to set up Froome but with the terrain making it tough to make an attack stick things came back together allowing Cobo off the hook for the second day in succession.
Ian Stannard gave us his take on the day after working hard in service of the team in sweltering conditions including a rundown on the challenge for the early intermediate sprint.
He said: "I had a very busy start to the day because it my job was to look out for Froomey and to try and get him into contention to contest the first intermediate sprint after 19.7km. We were among several teams who made sure no breakaway attempts were allowed to stick before that occurred, but it was Rodriguez, (David) De la Fuente and (Bauke) Mollema who took the bonus seconds in the end.
"That took it out of me for a while and I suffered all the way up the Puerto de la Granja. That was when I took on the water carrier role with Xabier Zandio and we were pretty much constantly heading and forth to the cars to keep everybody cool and hydrated.
"As we approached Bilbao I then headed towards the front of the bunch and helped lead out Froomey and Brad onto that last climb which they took on two times. Once that had happened my job for the day was done and I was able to roll home in the gruppetto. It was like a sauna today."
Sports Director Steven de Jongh was happy with the effort the team put in when it came to taking the fight to the race leader.
He said: “It went pretty well in terms of the way we applied ourselves but unfortunately Cobo was just too strong. We tried to put him under pressure right from the start and Thomas Löfkvist was unbelievable today. He did some really good work for the team during that second half of the race and then Bradley then took up the mantle for Froomey on that final climb.
“Froomey did everything he could to try and shake Cobo but he just stuck to his wheel. When Mollema went soon after that, Bradley was strong enough to keep up with him, which was good to see and he was able to defend his third-placed position.
"Froomey will be wearing the white jersey again for Cobo tomorrow but unfortunately we couldn’t get the red jersey off him no matter how hard we tried. We will see what happens tomorrow.”