Head Coach John Fletcher's side made an explosive start, scoring twice within the first five minutes, first through Skelcey who was on the end of a fluid passing move before Andrew Boyce was on hand to dive over after a good break from scrum half James Mitchell.
Portugal got their first points on the board with a penalty from their fly half but England turned the screw and inside centre Fowlie scored between the posts - his third in two games.
Skelcey had his second of the game with 20 minutes played, showing an electric turn of pace to beat three defenders before touching down under the posts, Jennings converted to make it 26-3.
England went down to 14 men soon after when flanker Matt Bolwell was judged to have made a high tackle, but the disadvantage didn't have too much of an affect as Fowlie went over for his second try and Lewis Boyce ran one in from over 22 metres out.
Skelcey had his hat-trick early in the second half, a nice break from Nick Tompkins freed up space and the Northampton wing touched down in the corner to make it 41-3.
England's eighth try came from wing Perkins who gathered a nice pass and darted over the line with Mitchell converting. Portugal gave the crowd something to cheer when their scrum half spotted a gap in England's defence to touch down but two tries from Chisholm and one from Farthing made the scoreline 65-8.
Hooker James burrowed over after a rolling maul for England's thirteenth try before Townsend rounded off the scoring with the final play of the game.
Hat-trick man Skelcey was delighted to get the win and make a statement, he said: "It was important to pay the utmost respect to Portugal and we did that. It's pleasing to score so many tries and I'm pretty happy to get three, but as a team we've got to be happy with that performance - we've made a good statement and now we move onto the next game."
Points: Skelcey 3T, A. Boyce 1T, Fowlie 2T, L Boyce 1T, Perkins 1T, Chisholm 2T, Farthing 1T, James 1T, Hewitt 1T, Townsend 1T; Jennings 4C, Mitchell 2C
15 Louis Clayton-Molloy (London Wasps & Harrow School)
14 George Perkins (Saracens & Oaklands College)
13 Lucas Slowik (Bristol Rugby & Filton College)
12 Tom Fowlie (London Irish & St Pauls Catholic College)
11 Josh Skelcey (Northampton Saints & Moulton College)
10 Rory Jennings (Bath Rugby & Bryanston School)
9 James Mitchell (Sale Sharks & Lymm School)
1 Lewis Boyce (Leeds Carnegie & Prince Henry's Grammar)
2 Sam James (Saracens & Bishops Stortford)
3 Neale Farthing (Leicester Tigers & Wyggeston & Queen Elizabeth College)
4 Charlie Hewitt (Exeter Chiefs & Ivybridge College)
5 Josh Peters (Northampton Saints & Oundle School)
6 Matt Bolwell (Exeter Chiefs & Truro College)
7 Andrew Boyce (Worcester Warriors & Kings Worcester)
8 Charlie Ewels (Bath Rugby & Bryanston School) (Capt)
16 Jack Walker (Leeds Carnegie & Prince Henry's Grammar)
17 Luke Chapman (Exeter Chiefs & Truro College) on for Lewis Boyce 55 mins
18 Paul Hill (Leeds Carnegie & Prince Henry's Grammar) on for Neale Farthing 55 mins
19 James Chisholm (Harlequins & Brighton College) on for Charlie Ewels 35 mins
20 Andrew Hughes (Sale Sharks & Hartpury College)
21 Stuart Townsend (Exeter Chiefs & Ivybridge College) on for Tom Fowlie 55 mins
22 Nick Tompkins (Saracens & Oaklands College) on for Lucas Slowik 30 mins
23 Howard Packman (Northampton Saints & Moulton College)
24 Jordan Onjoaife (Northampton Saints & Stowe School)
25 Josh Sharp (Saracens & Oaklands College)
26 Tom Howe (London Wasps & Shiplake College)