Ian Humphreys kicked a late winning penalty after Marland Yarde crossed twice as London Irish upset Worcester Warriors 20-18 at Sixways on Saturday.
In a tightly fought opening half, Worcester went into a 10-3 lead through a converted David Lemi try and an Ignacio Mieres penalty, with Humphreys responding for Irish.
However, Yarde touched down for the Reading-based outfit before the interval and added a second not long after the break as they took the lead for the first time.
Mieres looked to be the hero when his three-pointer and try gave the Warriors the advantage with 11 minutes to go, but Humphreys snatched the win with a late penalty.
Both of these sides were tipped to struggle at the start of the season and suffered heavy losses in round one of the Premiership. The Warriors were comfortably defeated 32-15 by Leicester Tigers while the visitors went down 42-20 to Saracens.
It unsurprisingly proved to be a cagey opening with Mieres and Humphreys trading penalties before the hosts found their attacking game and Lemi scampered over.
With the pressure now coming on from the Worcester pack, Chris Hala'ufia found himself off the field for 10 minutes after being sin-binned.
But Dean Ryan's men couldn't take advantage and it was London Irish who were next to strike through England international Yarde as the teams went into half-time level.
That late score in the first period gave the visitors the momentum going into the second half and it was no surprise to see them take the lead.
Once again it was Yarde who was on the end of it and Humphreys' conversion gave them a seven-point buffer. However, Mieres steadied the ship with a penalty before the fly-half crossed the whitewash to dramatically regain Worcester's advantage.
But undeterred, Brian Smith's side went up the other end and an infringement allowed Humphreys to win the game from the tee.
Tries: Lemi, Mieres
Pens: Mieres 2
For London Irish:
Tries: Yarde 2
Cons: Humphreys 2
Pens: Humphreys 2
Worcester Warriors: 15 Chris Pennell, 14 Josh Drauniniu, 13 Ravai Fatiaki, 12 Josh Matavesi, 11 David Lemi, 10 Ignacio Mieres, 9 Paul Hodgson, 8 Semisi Taulava, 7 Sam Betty, 6 Jonathan Thomas (capt), 5 Chris Jones, 4 Mike Williams, 3 Euan Murray, 2 Ed Shervington, 1 Paul Andrew.
Replacements 16 Nick Seymour, 17 Ofa Fainga'anuku, 18 John Andress, 19 Dean Schofield, 20 Jake Abbott, 21 Jeremy Su'a, 22 Danny Gray, 23 Jon Clarke.
London Irish: 15 Topsy Ojo, 14 Marland Yarde, 13 Guy Armitage, 12 Eamonn Sheridan, 11 Andrew Fenby, 10 Ian Humphreys, 9 TomÃ¡s O'Leary (capt), 8 Chris Hala'ufia, 7 Ofisa Treviranus, 6 Jon Fisher, 5 Kieran Low, 4 Nic Rouse, 3 Halani Aulika, 2 David Paice, 1 Matt Parr.
Replacements: 16 Jimmy Stevens, 17 John Yapp, 18 Leo Halavatau, 19 Bryn Evans, 20 Jebb Sinclair, 21 Declan Danaher, 22 Shane Geraghty, 23 Darren Allinson.
Referee: Tim Wigglesworth
Assistant referees: Roy Maybank, Andrew Pearce
Timekeeper: Mike Hamlin
Television match official: Rowan Kitt
Assessor: Nigel Yates