Edinburgh produced the first major shock of Heineken Cup 2011/12 by overcoming London Irish 20-19 at Madejski Stadium on Saturday.
The home outfit were nine points up with 24 minutes remaining in Reading, but were then stunned by a late fightback from the Scots.
London Irish had put themselves 6-0 to the good early on thanks to a couple of penalties from Tom Homer. But then the visitors struck courtesy of wing Lee Jones. Harry Lenoard, who missed an early penalty, added the conversion for the lead.
Youngster Homer did respond with his third penalty goal and then converted a try from his half-back Ross Samson just before the half-hour.
Leonard did cut the lead down to six though with another penalty knocked over before the break.
Six minutes after the resumption, Homer added another penalty but it was the Scots who claimed the vital next score, with number eight Stuart McInally going over for their second. Busy scrum-half Greig Laidlaw converted and then three more points on 68 minutes.
The hosts threw the kitchen sink at their visitors during the closing stages but it was to no avail as their hopes of topping Pool Two hit a major and unexpected speedbump.
For London Irish:
Pen: Homer 4
Tries: Jones, McInally
Con: Leonard, Laidlaw
Pen: Leonard, Laidlaw
London Irish: 15 Tom Homer, 14 Topsy Ojo, 13 Steven Shingler, 12 Shontayne Hape, 11 Adam Thompstone, 10 Dan Bowden (capt), 9 Ross Samson, 8 Jebb Sinclair, 7 Jamie Gibson, 6 Bryn Evans, 5 Matt Garvey, 4 Nick Kennedy, 3 Paulica Ion, 2 James Buckland, 1 Alex Corbisiero.
Replacements: 16 Brian Blaney, 17 Max Lahiff, 18 Faan Rautenbach, 19 James Sandford, 20 Richard Thorpe, 21 Joe Ansbro, 22 Adrian Jarvis, 23 Paul Hodgson.
Edinburgh: 15 Jim Thompson, 14 Lee Jones, 13 Nick de Luca, 12 Matt Scott, 11 Tim Visser, 10 Harry Leonard, 9 Mike Blair, 8 Stuart McInally, 7 Ross Rennie, 6 David Denton, 5 Grant Gilchrist, 4 Esteban Lozada, 3 Geoff Cross, 2 Ross Ford (c), 1 Allan Jacobsen.
Replacements: 16 Steven Lawrie, 17 Kyle Traynor, 18 Lewis Niven, 19 Sean Cox, 20 Roddy Grant, 21 Greig Laidlaw, 22 James King, 23 Tom Brown.
Referee: Romain Poite (France)