For much of Ferguson's 24-year reign at Old Trafford it has been Arsenal who have provided the main resistance to his empire-building and the old rivals go head to head with their title hopes at stake once again.
Ferguson fulfilled his ambition to knock Liverpool "off their perch" at the top of English football years ago and Chelsea have only emerged as serious challengers in recent years, but Arsenal, whether managed by Arsene Wenger or George Graham, have always been a thorn in United's side. From the moment Arsenal defender Nigel Winterburn launched a tirade of abuse at Brian McClair following the United star's missed penalty in an FA Cup tie in 1988, there has been an extra edge to clashes between these super-powers.