Sir Alex Ferguson has paid a glowing tribute to old rival and 'friend' Arsene Wenger after the Arsenal boss announced he will leave at the end of the season.
Wenger and the legendary Manchester United boss locked horns from 1996 until Ferguson retired from management at the end of the 2012/13 campaign, and were regularly at each other's throats on the sidelines as they eyed wins for their respective sides.
However, underlying their rivalry was a close friendship and the duo got on swimmingly out of the dugout, as Ferguson alluded to in an interview with United's official site.
Indeed, the Scot explained why he had so much respect for the veteran Frenchman and believed that his longevity - Wenger has been at the helm for 22 seasons - was down to his professionalism and hunger to win every game that he could.
Ferguson revealed: "I am really happy for Arsene Wenger. I have great respect for him and for the job he has done at Arsenal.
"It is great testament to his talent, professionalism and determination that he has been able to dedicate 22 years of his life to a job that he loves. In an era where football managers sometimes only last one or two seasons, it shows what an achievement it is to serve that length of time at a club the size of Arsenal.
"I am pleased that he has announced he is leaving at this stage of the season, as he can now have the send-off that he truly deserves.
"He is, without doubt, one of the greatest Premier League managers and I am proud to have been a rival, a colleague and a friend to such a great man."
Perhaps the greatest contest between the two teams was the 1999 League Cup semifinal showdown, while other notable clashes between United and Arsenal included the infamous 'Pizzagate' saga after the October 2004 game and the September 2003 encounter that saw tempers flare after Ruud Van Nistelrooy's penalty miss.