After Scotland had taken an early lead with a penalty, Purdy claimed the opening England score, making space for himself to add a smart finish.
Leicester colleague Will Owen started in the No7 shirt and prop Harry Rudkin gained his first cap at this level as a 70th-minute replacement.
Purdy’s fellow wing Zach Kibirige (2), centres Nick Tompkins and Tom Stephenson, lock Maro Itoje and No8 James Chisholm claimed the other tries with fly-half Billy Burns kicking nine points and replacement Sam Olver scored four.
Head coach Nick Walshe said: “We knew it would be a tough game and so it proved. Scotland fronted up but I’m pleased that we were able to perform well and score some nice tries. We’ve got a bit of time off now, so we’ll look at the game and regroup before we take on Ireland in our first home game.”
England Under-20s
15 Nathan Earle (Saracens)
14 Zach Kibirige (Newcastle Falcons)
13 Nick Tompkins (Saracens)
12 Tom Stephenson (Northampton Saints)
11 Henry Purdy (Leicester Tigers)
10 Billy Burns (Gloucester Rugby)
9 Callum Braley (Bristol Rugby)(c)
1 Danny Hobbs-Awoyemi (Northampton Saints)
2 Jack Walker (Leeds Carnegie)
3 Paul Hill (Leeds Carnegie)
4 Maro Itoje (Saracens)
5 Charlie Ewels (Bath Rugby)
6 Ross Moriarty (Gloucester Rugby)
7 Will Owen (Leicester Tigers)
8 James Chisholm (Harlequins)
Replacements:
16 Tom Woolstencroft (Bath Rugby) on for Jack Walker 63 mins
17 Alex Lundberg (London Wasps) on for Danny Hobbs-Awoyemi 46 mins
18 Harry Rudkin (Leicester Tigers) on for Paul Hill 70 mins
19 Tom Ellis (Bath Rugby) on for Ross Moriarty 49 mins
20 Joel Conlon (Exeter Chiefs) on for Joel Conlon 65 mins
21 Stuart Townsend (Exeter Chiefs) on for Callum Braley 65 mins
22 Sam Olver (Northampton Saints) on for Billy Burns 46 mins
23 Howard Packman (Northampton Saints) on for Tom Stephenson 48 mins
