Ex-Ulster star Best signed for Northampton in February
Northampton's appeal against Ireland flanker Neil Best's 18-week ban for eye-gouging has been dismissed by a Rugby Football Union panel.
Best was cited for making contact with the eye or eye area of Wasps forward James Haskell with his hand in the Premiership match on 20 September.
The 29-year-old was playing only his third competitive game after joining Saints from Ulster in the summer.
He is not allowed to play again until 27 January, 2009.
Best's suspension rules him out of Ireland's three November internationals and 17 Northampton first-team games across the Guinness Premiership, the EDF Energy Cup and the European Challenge Cup.
Haskell was taken to hospital after the game and found to have abrasions and swelling around his eyes, while the player complained his vision had been affected.
At the initial hearing, chaired by RFU disciplinary officer Jeff Blackett, Best said he had acted "recklessly but not deliberately" and received character testimonials from his former Ulster coach Alan Solomons and Saints director of rugby Jim Mallinder.
The panel accepted Best, who apologised to Haskell on the field, did not intend to cause serious injury but judged the offence to be towards the top end of the scale of seriousness.
The range of punishments for Best's offence varied from a six-week ban to a maximum of three years.
Northampton's Dylan Hartley received a six-month suspension last year after being found guilty on two counts of eye-gouging, also against Wasps.
Those incidents also involved Haskell, together with former Wasps flanker Johnny O'Connor.