Omar Fraile took his maiden Grand Tour victory on stage 11 of the Giro d’Italia as Tom Dumoulin hung on to the overall lead despite a frantic and stressful day in the pink jersey.

Team Dimension Data’s Fraile won the 161-kilometre stage from Firenze to Bagno di Romagna out of the remnants of a large breakaway which at one point threatened to knock Dumoulin off top spot, and forced his Team Sunweb squad to work hard all day to limit their losses.

The pre-race favourite Nairo Quintana, second in the general classification, crossed the line in the same group as Dumoulin, a little over 90 seconds behind Fraile. But Quintana’s team-mate Andrey Amador was in the break and moved up to sixth overall, 3min 5sec back overall to give the Movistar squad plenty of options for the days to come.

Fraile had been aggressive in the break but it came down to a select sprint between the final four survivors as he beat Rui Costa (UAE Team Emirates), Pierre Rolland (Cannondale-Drapac) and Tanel Kangert (Astana) to the line.

A furious pace from the start of the day split the peloton into pieces and allowed Dumoulin’s rivals to test the strength of Sunweb over the day’s four classified climbs and the long descent to the finish. Amador was at one point the virtual race leader as the breakaway moved five minutes clear but it soon began to splinter.

Fraile went clear with Team Sky’s Mikel Landa, with the British squad forced into being creative after the crash on Sunday appeared to have knocked both Landa and Geraint Thomas out of contention. They were reeled in on the final climb before Fraile chased down an attack from Rolland and the pair went clear to crest the summit first and set up the long chase to the finish. Fraile’s victory was Dimension Data’s first in the Giro.

Behind, the defending champion Vincenzo Nibali (Bahrain-Merida) and Thibaut Pinot (FDJ) launched attacks which split the peloton further, dropping Thomas and creating further time gaps in the general classification.

Dumoulin leads by 2min 23sec from Quintana, with Trek-Segafredo’s Bauke Mollema a further 15sec back in third. Pinot is fourth, 2min 40sec down and seven seconds ahead of Nibali in fifth. Thomas gave up another 48sec to the main contenders to sit 14th overall, 6min 21sec.

Tom Dumoulin makes a descent during stage 11. Photograph: Luk Benies/AFP/Getty Images

Stage 11 results (Florence to Bagno di Romagna, 161 km)

1) Omar Fraile (Dimension Data) 4:23:14”. 2) Rui Costa (UAE Team Emirates) ST. 3) Pierre Rolland (Cannondale). 4) Tanel Kangert (Astana). 5) Giovanni Visconti (Bahrain). 6) Ben Hermans (BMC Racing). 7) Dario Cataldo (Astana). 8) Simone Petilli (UAE Team Emirates). 9) Maxime Monfort (Lotto) +3”. 10) Laurens De Plus (Quick-Step).

General classification after stage 11

1) Tom Dumoulin (Sunweb) 47:22:07”. 2) Nairo Quintana (Movistar) +2:23”. 3) Bauke Mollema (Trek) +2:38”. 4) Thibaut Pinot (FDJ) +2:40”. 5) Vincenzo Nibali (Bahrain) +2:47”. 6) Andrey Amador (Movistar) +3:05”. 7) Bob Jungels (Quick-Step) +3:56”. 8) Tanel Kangert (Astana) +3:59”. 9) Domenico Pozzovivo (AG2R) +4:05” .10) Ilnur Zakarin (Katusha) +4:17”.