Rome - Team Sky rider Wouter Poels capped a thrilling solo attack with victory and the overall leader's jersey after the fourth stage of the Tirreno-Adriatico on Saturday.
Poels, claiming his first win of the season, countered Italian Giampaolo Caruso after the Katusha rider tried to distance a small leading peloton on the final metres of the Crispiero climb whose summit is 5km from the finish line.
The tall Dutchman went on to hold off a small group of chasers to cross the finish line solo and take the leader's blue jersey from Belgian Greg Van Avermaet (BMC).
"It's really unbelievable," Poels told Italian television Rai.
"I had good legs, so it's nice if you can attack like this and take the victory."
Poels came over the finish line 14secs ahead of Rigoberto Uran, who sprinted ahead of a small group containing Joaquin Rodriguez, Alexis Vuillermoz and defending champion Alberto Contador among others.
The pace of Vuillermoz and AG2R teammate Rinaldo Nocentini on the final kilometres of the Crispiero climb proved fatal to any hopes Van Avermaet had of holding on to the blue jersey for another day.
Their speed at the front left the Belgian trailing off the pace before he finished over two minutes behind Poels.
Poels made his move with just over 6km to race, leaving Caruso in his wake with ease after the Italian's brief attempt to pull free.
Once over the crest of the climb, the Dutchman hit full gas on his way towards victory.
"It was perfect timing. I was looking a little bit at some of the big riders like (Alberto) Contador and (Vincenzo) Nibali, but I felt I had the legs and thought maybe I'd attack over the top of the climb. Then you only have to do the downhill. It worked pretty good!" added Poels.
One of the biggest losers on the day was Italian Vincenzo Nibali, who lost eight seconds to Contaco in the race for overall victory after paying for his earlier efforts on the climb when he failed to follow Contador's group at the finish.
Although Uran is now second overall at 17sec behind Poels, Nibali, in ninth, and Contador, in 10th, are only 31 and 32 off the leading pace ahead of Sunday's key climbing stage which begins in Esanatoglia and ends with a 16km ascent to the summit of Terminillo.
Stage 4 results from Tirreno - Adriatico (Indicatore - Castelraimondo, 226 km)
1. Wout Poels (Netherlands / Team Sky) 5:53:38"
2. Rigoberto Uran (Colombia / Etixx - Quick-Step) +14"
3. Joaquim Rodriguez (Spain / Katusha)
4. Alexis Vuillermoz (France / AG2R)
5. Rinaldo Nocentini (Italy / AG2R)
Classification of the Tirreno - Adriatico after Stage 4
1. Wout Poels (Netherlands / Team Sky) 14:28:18"
2. Rigoberto Uran (Colombia / Etixx - Quick-Step) +17"
3. Steven Cummings (Britain / Team MTN) +26"
4. Thibaut Pinot (France / FDJ)
5. Roman Kreuziger (Czech Republic / Tinkoff - Saxo) +27"
6. Jonathan Castroviejo (Spain / Movistar) +28"
7. Bauke Mollema (Netherlands / Trek)
8. Peter Sagan (Slovakia / Tinkoff - Saxo) +30"
9. Vincenzo Nibali (Italy / Astana) +31"
10. Alberto Contador (Spain / Tinkoff - Saxo) +32"