Alberto Contador won a battle of the heavyweights against Chris Froome but before they sparred at the finish, two riders were disqualified on stage 16 of the Vuelta a España for exchanging punches on the road.

Contador claimed his first stage win on the summit finish at La Farrapona to extend his overall lead, pulling away from Team Sky’s Froome with one kilometre left and the rest of the field left in the distance.

Behind them the recriminations were still flying after Contador’s Tinkoff-Saxo team-mate Ivan Rovny and Omega Pharma Quick-Step’s Gianluca Brambilla had come to blows while part of the day’s breakaway, leading to both riders being disqualified mid-stage.

The result sees Contador stretch his advantage in the general classification to 1min 36sec over Movistar’s Alejandro Valverde, with Froome three seconds further back in third place.

A month ago, Contador was insisting he would not be fit to ride his home Grand Tour but now he seems destined to win it. The queen stage of this year’s Vuelta exceeded all expectations with plenty of drama between the four category one climbs of the 160.5km run from San Martín del Rey Aurelio.

A 13-man break had animated the stage, with Sky’s Peter Kennaugh, Movistar’s Adriano Malori and Tinkoff-Saxo’s Rovny all making sure their teams were represented.

That meant Katusha’s Joaquim Rodríguez was the only one of the main GC contenders without a team-mate up there, and he had yet bigger problems when Contador, Froome and Valverde jumped out from the pack on the first climb – an early taste of the fireworks to come.

Katusha reeled the trio in as the break went clear, enjoying a lead of more than eight minutes as they approached the second climb.

Despite that gap, the pace remained high, putting the squeeze on Omega Pharma Quick-Step’s Rigoberto Uran, who saw his GC hopes effectively ended as he struggled to keep pace with the pack, suffering the effects of illness.

The third climb saw Trek Factory’s Fabian Cancellara break clear of the peloton but the stage was still only simmering.

It boiled over up the road, where an argument between Rovny and Brambilla in the break saw the pair come to blows in an extended exchange. Shortly after, the race officials’ car pulled alongside Brambilla and signalled his disqualification but, rather than climb off, the angry Italian waited for Rovny and remonstrated some more before taking his leave.

Rovny raced on but it was soon his turn to get the signal from the officials.

With the breakaway splintering, Sky were keeping the hammer down on the front of the peloton – Kennaugh having dropped back to help out – and the gap to the leaders tumbled rapidly.

Contador suffered a scare when he dropped back for a change of bike and was almost taken out by a press motorcycle but he was quickly back on the wheel of Sky and ready for the grand finale.

Twelve kilometres from the finish Alessandro De Marchi (Cannondale) left the final remnants of the break behind in a bid for solo victory but this would be a day for the big guns.

As the road ramped up on the steep climb to the finish, Froome burst forward with 4km to go, and only Contador could go with him as Valverde and Rodriguez were quickly distanced.

All Contador needed to do was hold his wheel as they swept past De Marchi – and he did that when Froome rose out of the saddle in a bid to shake him off 2.5km from home.

It was then the Spaniard’s turn and when he made his move in the final kilometre Froome had no answer.