Cannock had opened the scoring with a well-worked penalty corner from Paul Edwards 18 minutes into the game. Richard Gibson equalised for East Grinstead, John Mills restoring Cannock's lead just after the interval at another penalty corner. A penalty stroke from Jason Lee then put the teams level again at 2-2 until Mayer's decisive run.
The weather, meanwhile, hit the leading clubs, leaving Southgate, Hounslow and Havant idle after their matches were postponed.
The veteran Neil Mallett put Bournville ahead in the 26th minute against Indian Gymkhana, who came back with late goals from Simon Samuel and James Michael for their first league win.
At Slough, Reading notched four without reply when the penalty-corner specialist, Paddy Osborn, scored twice from open play. Howard Hoskin and Chris Keevil completed the scoring.
Teddington went down 2-0 at Stourport, whose goals came from David Knott and Owen Jones. In the day's only other First Division game at Southampton, Trojans beat Firebrands 5-1.
In the Second Division, Surbiton, with goals from Jon Molloy and Simon Tinkler, beat Isca 2-0 at Exeter to maintain their three-point lead over Guildford and Barford Tigers.
Guildford, with Ian Jennings and the Dutchman Jos Donker scoring twice, beat Cambridge City 4-2, while Tigers accounted for Gloucester City with goals from Darminder Singh and Hardip Matharu.Reuse content