Gatting scored 96 and Haynes an unbeaten 84, their stand of 166 in 26 overs for the second wicket making short work of Northamptonshire's 221 for 5 as Middlesex strolled in by eight wickets and with 20 balls to spare.
It was good to hear, meanwhile, that Angus Fraser had stepped in earlier with the wickets of Alan Fordham (54) and Allan Lamb (41) as the pair looked to push things along and capitalise on a score that read 129 for 1 at one stage.
Surrey, who started the day a clear third in the table behind Middlesex and Essex, were caught by Warwickshire in all senses at The Oval, Allan Donald donning his Sunday best in a comfortable win by six wickets. The South African took 4 for 23, Surrey's total of 132 in 34 overs their second lowest in the League this summer.
Somerset also pulled up alongside Surrey, an opening stand of 169 between Mark Lathwell (96) and Andy Hayhurst (67 not out) ensuring a nine-wicket success at Grace Road, where Leicestershire have not won a single League match since May of last year.Reuse content