The Deceuninck-QuickStep star caught breakaway rider Tim Wellens of Belgium at the top of the Côte de Mutigny with 16 kilometres to go and having continued solo, he held off the peloton to take the win.

He won the 215km stage from Binche to Épernay in a time of 4 hours 40min 29sec.

Australia’s Michael Matthews of Team Sunweb and Belgium’s Jasper Stuyven of Trek–Segafredo were second and third, respectively, as two of 11 riders that finished 26 seconds back.

"I’m speechless," Alaphilippe said.

"I don’t realise what’s happening to me.

"I knew this stage suited me.

"I managed to avoid any pitfalls and crashes.

"I felt good so I accelerated in the Mutigny climb but I didn’t think I’d go alone.

"I gave everything."

Alaphilippe holds a 20-second advantage over Belgium's Wout van Aert in the general classification.

His overall time stands at 9:32:19.

Van Aert's Jumbo-Visma team-mate Steven Kruijswijk is 25 seconds off the pace in third.

Overnight leader Mike Teunissen, also of Jumbo-Visa, finished nearly five minutes down today in 80th place.

He has dropped to 72nd spot in the overall rankings.

Defending champion Geraint Thomas of Britain lost five seconds on two of his rivals – Ineos co-leader Egan Bernal of Colombia and France's Thibaut Pinot of Groupama–FDJ – at the finish.

He lies in seventh place in the general classification, 45 seconds back.

Stage four is due to take place tomorrow.

It is a 213.5km route from Reims to Nancy.

The 21-stage event is scheduled to conclude on July 28.