England’s powerful pack helped them win the Under-20 Six Nations title for the fourth time in five years when they scored 18 points against France without reply after the interval at Brighton’s Amex Stadium.

It was the first rugby match at the stadium that will host two games in next autumn’s World Cup.

Victory was secured only in the final 10 minutes in a winners-take-all encounter between the joint leaders of the tournament. England were holding on to a one-point lead when their replacement scrum-half, Stuart Townsend, cleverly kicked to the corner and then deflected a clearing kick by France’s right-wing, Alexandre Pilati.

The ball landed in the arms of the Harlequins centre, Joe Marchant, who acrobatically kept his feet clear of the touchline before touching down.

Minutes later Sam Skinner, another replacement, gave the Saracens wing George Perkins a clever pass to run in a second try under the posts. France, who included Damian Penaud, the son of the former France fly-half Alain Penaud, in the centre, then suffered a series of injuries including one to the captain, Lucas Bachelier, and lost grip of the title they won last season.

England’s other points came from the boot of the Bath fly-half, Rory Jennings, and for the second successive week their No8, James Chisholm, who hails from Sussex, was named man of the match. England, the Under-20 world champions, had lost the first match of this year’s Six Nations in Wales.

France had a try disallowed after half an hour when the TMO, Derek Bevan, ruledBachelier had knocked the ball on before the prop Thibault Estorge crashed over the line.

England failed to get out of their 22 and moments later the No8, Fabien Sanconnie, battered his way over the line for the first try of the evening. Their full-back, Thomas Ramos, scored two penalties.