Sergio Henao and Rigoberto Urán both finished just 11 seconds back as Paolo Tiralongo (Astana) won a thrilling seventh stage of the Giro d'Italia and Ryder Hesjedal (Garmin-Barracuda) moved into the overall lead.
Henao crossed the line in 11th while fellow Colombian Urán was 24th as they moved up the general classification.
Urán is now 15th, 53 seconds behind Hesjedal, while Henao is 22nd, 1:10 adrift. They are also third and fifth respectively in the young rider standings.
The first mountain stage of the race, which took the riders 205 kilometres from Recanati, only really came to life on the final climb up to Rocca di Cambio.
Lampre-ISD had looked to set it up for local hero Michele Scarponi and he launched his attack on one of the steepest sections inside the final kilometre.
But Tiralongo was able to jump from the pack and he used his finishing kick to good effect as he pushed himself to the limit to take the win from Scarponi.
Fränk Schleck (RadioShack-Nissan) was third, three seconds back, stage favourite Joaquim Rodríguez (Katusha) fourth and Hesjedal fifth.
With previous leader Adriano Malori (Lampre-ISD) having been dropped early on the climb, it means that Hesjedal is the new holder of the maglia rosa.
He has a 15 seconds advantage from Tiralongo, with Rodríguez a further two seconds back in third.
Sports Director Steven de Jongh was happy to see both Henao and Urán in the mix in what was the first real skirmish between potential GC contenders.
He told us: "They didn’t lose much time and were right up there so that was good.
"Everybody is helping out each other and the atmosphere is great, as you’d expect after that second win. All the work the Colombians did there was really appreciated and now the boys are helping them."
The late drama was in contrast to what had gone before on a stage which featured more than 3,000 metres of climbing. A break moved clear straight away and within 30km the four riders in question - Fumiyuki Beppu (Orica-GreenEDGE), Reto Hollenstein (NetApp), Matteo Rabottini (Farnese Vini) and Mirko Selvaggi (Vacansoleil-DCM) – quickly built up a lead of just over nine minutes.
Perhaps as a reaction to what had proved a surprisingly tough stage 24 hours earlier, the pace was far more sedate in the benign weather conditions, with the average speed 33km/h for the first three hours of the day.
Team Sky made sure Henao and Urán were protected throughout, with world champion and dual stage winner Mark Cavendish among those working for them as he was on water bottle duty.
The escape quartet’s lead held steady at just under eight minutes for much of the day - it was still 7:40 with 70k to go - but that all changed when the Lampre-ISD team of Malori were joined on the front with 35km to go by Garmin-Barracuda and then Katusha.
The gap came down rapidly thereafter and by the base of the final climb with 19km remaining it had dipped under two minutes and Rabottini was out on his own having left his fellow escapees.
A fierce pace on the early slopes initially caused plenty of splits but it soon settled down and Rabottini was joined by Stefano Pirazzi (Colnago-CSF) and José Herrada (Movistar) at the head of affairs.
As the Farnese rider eventually dropped back the other two still had 15 seconds in hand going into the last 2km but any chance Pirazzi had disappeared when he lost all momentum as he had to swerve around a motorbike. Herrada gave it his all but he too was eventually swallowed up as Scarponi and then Tiralongo took centre stage.
Henao and Urán stayed right in touch just in behind as they finished in the top 25 to maintain their overall ambitions.
DS de Jongh added: "The climbs were more steady today and there was a small breakaway which went in the first kilometre so it was easier to control for Lampre and they were then helped by Garmin and Katusha.
The climbers should again be to the fore in Sunday's 229km eighth stage which is up and down right from the off at Sulmona and only flattens out in the final 5km run into Lago Laceno.
"They go 20km uphill at the start so it’s not going to be a fun start for many of them," said de Jongh. "I think Sergio and Rigoberto can be right up there again at the end."