England U20s sealed their first Grand Slam since 2011 after a hard-fought 14-10 victory over Ireland in Dublin.
England led 14-3 at the break with tries from Jack Nay and Henry Walker, while Max Malins sent over two conversions.
Bill Johnston kicked a penalty for Ireland in between those scores who went into half-time trailing by 11 points.
Gavin Coombes scored for Ireland just after the hour mark with Johnston’s conversion reducing the deficit to 14-10 however, England held on for victory.
"I'm incredibly proud of the character of this team," said England U20 captain Zach Mercer. "We have shown that spirit throughout the competition and to defend like we did today was outstanding."
The win gives England U20 their first Six Nations Grand Slam since 2011 and Mercer believes it was resilience that kept up their unbeaten run.
"We showed a huge amount of belief in the way we performed. We were resilient and Ireland put us under pressure but I knew we would pull through because this team has that confidence. We have put in a lot of hard work.
“It hasn't quite kicked in that we have won the Grand Slam but I am over the moon."
England U20 coach Tom Williams said: “We made it hard for ourselves, however the team have shown a lot of backbone and character today and that is what is so promising about this group of players.
“We know we can’t rest on our laurels and there is a lot to work on ahead of the U20 World Championship but we have a good platform to build from.”
15. Tom Parton (London Irish)
14. Joe Cokanasiga (London Irish)
13. Dominic Morris (Saracens)
12. Will Butler (Worcester Warriors)
11. Sam Aspland-Robinson (Harlequins)
10. Max Malins (Saracens)
9. Harry Randall (Gloucester Rugby)
1. Ollie Dawe (Bristol Rugby)
2. Henry Walker (Gloucester Rugby)
3. Ciaran Knight (Gloucester Rugby)
4. Jack Nay (Saracens)
5. Nick Isiekwe (Saracens)
6. Tom Curry (Sale Sharks)
7. Ben Curry (Sale Sharks)
8. Zach Mercer (Bath Rugby) captain
16. Jamie Blamire (Newcastle Falcons)
17. Ralph Adams-Hale (Saracens)
18. Joseph Morris (Worcester Warriors)
19. Justin Clegg (Worcester Warriors)
20. Josh Bayliss (Bath Rugby)
21. Alex Mitchell (Northampton Saints)
22. Theo Brophy Clews (London Irish)
23. Max Wright (Yorkshire Carnegie)
Tries: Nay, Walker
Conversions: Malins (2)
England U20’s 2017 Six Nations results:
England 59 - 17 France: Saturday 4th February – Sandy Park, Exeter
Wales 21 - 37 England: Friday 10th February – Eirias Park, Colwyn Bay
England 46 - 0 Italy: Friday 24th February – Darlington Mowden Park
England 33 - 5 Scotland: Saturday 11th March – Franklin’s Gardens, Northampton
Ireland 10 - 14 England: Friday 17th March – Donnybrook Stadium