Wasps established a five-point cushion between themselves and Northampton - their nearest rivals before the start of play - in a scrappy encounter which was always in danger of bubbling over.

The Londoners made the most of home advantage to strengthen their grip on fifth place but it was certainly not a sparkling performance from them.

Kick-off was delayed by 15 minutes because of traffic congestion in the Wycombe area and delays to train services but the delay did not appear to affect the visitors , who took the lead in only the second minute through Paul Grayson's 20m penalty which hit the posts on its way through.

Wasps fly-half Alex King responded with a kick from close range but one minute later Grayson put the Saints ahead with another penalty.

But Wasps hit back with the only try of the game when prop Trevor Leota touched down after getting away from a rolling ball. King converted and then added a close-range penalty at the start of the second half.

Northampton's woes continued when referee Roy Maybank sin-binned prop Matt Stewart in the 47th minute but he was joined on the sidelines by Wasps lock Simon Shaw after he was sent from the field for tripping.

The loss of these players appeared to affect both sides, although Grayson kicked Northampton closer to their hosts with a long-range penalty in the 57th minute.

But seconds from the final whistle, deep into injury time, King's drop goal sealed victory for Wasps.