Wasps tightened their grip on fifth place in the Zurich Premiership with a hard-fought win over their closest challengers Northampton.

Both sides had a man sin-binned in a scrappy contest that was ultimately settled by a lone try from Wasps hooker Trevor Leota.

The match had been given a tetchy feel after a delay to the start, because of because of road congestion and train delays.

We had gone out and warmed up and I did wonder why Wasps were not out there. I don't call that good sportsmanship Northampton head coach Wayne Smith

Northampton claimed to have no knowledge of the delay and they felt that Wasps failure to tell them was against the spirit of the game.

"We had gone out and warmed up and I did wonder why Wasps were not out there. I don't call that good sportsmanship," said Northampton head coach Wayne Smith.

Wasps director of rugby Warren Gatland denied any bad sportsmanship, explaining that he was totally unaware Smith had not been told of the delay.

"The delay of the match was entirely due to the safety officer of the ground. It was made at 1430GMT, " he said.

"I presumed that information got to the opposition team as well."

Northampton were first to put points on the board through Paul Grayson's second-minute penalty, which hit the posts on its way through.

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

Match facts

Wasps 16 Try: Leota Con: King Pens: King (3) Northampton 9 Pens: Grayson (3)

However, Leota then struck for the decisive try, crashing over from a rolling maul.

King converted and then added a close-range penalty at the start of the second half to take the lead to 13-6.

Northampton's woes continued when referee Roy Maybank sin-binned prop Matt Stewart in the 47th minute.

But he was soon joined on the sidelines by Wasps lock Simon Shaw, who was yellow-carded for tripping.

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

But deep into injury time, King's drop goal sealed victory for Wasps.

Wasps: Van Gisbergen; Rudd, Abbott, Logan; King, Howley; Dowd, Leota, Green, Shaw, Birkett, Worsley, Volley, Dallaglio, Wood.
Replacements: Greening, Lewsey, Erinle, Scrivener, Lock, Kershaw.

Northampton: Beal; Reihana, Jorgensen, Leslie, Cohen; Grayson, Dawson; Thompson, Stewart, Williams, Lord, Seely, Pountney, Connors, Richmond. Replacements: Budgen, Hunter, Soden, Vass, Brooks, Tucker.

Referee: R Maybank (RFU)