Northampton coach Wayne Smith has slammed London Irish for ruining their Zurich Championship clash as a spectacle despite his side's 38-14 victory and a guaranteed place in next season's Heineken Cup.

Northampton's qualification was confirmed through Wasps losing at Sale, but Smith hit out after his side were faced by an Irish second team.

The Exiles claimed that a combination of injuries and players reaching their 32-game limit for the season had forced their hand in selection.

They fielded none of the Powergen Cup final team which defeated Northampton at Twickenham last month, and Smith could not conceal his anger.

"How do you prepare to play against a team that hasn't taken the competition seriously?" Smith said.

"We had a lot of injuries as well today, and there were guys playing who shouldn't have been, but they fronted up because we took the competition seriously.

"The game was a disaster as a spectacle, and the skill level was atrocious."

Irish had already qualified for the Heineken Cup before Sunday's encounter, but Smith added: "Had we already qualified, then we would have approached today in exactly the same way as we did.

"I come from a land were every time you pull on a shirt, you want to win," said the New Zealander.

Despite Northampton finishing three places above Bristol in the Zurich Premiership, they must now travel to the West Country early next month because Bristol have effectively taken over as top seeds following their surprise win at league champions Leicester yesterday.

"How can the fifth-placed team now play at the eighth team's ground? Do Monty Python set up this structure?

"I can't understand the structure," Smith said. "Maybe we would have been better off finishing eighth, playing against a team that didn't want to play in this competition, and then get a home semi-final.

"We deserve to play at Franklin's Gardens in the semi-finals. We will go to Bristol and give it everything, but home advantage is a huge advantage in the semi-finals."

Just 3,300 people watched Northampton triumph 38-14 at the Madejski Stadium, but Irish rugby director Conor O'Shea defended selection.

"We came into the play-offs with as strong a team as we possibly could field. Three Premiership games in eight days finished a lot of the guys off," O'Shea said.

"Today, we put out as strong a team as we possibly could," he added.

Irish technical coach Gary Gold sympathised with Northampton, that they now must travel to Bristol.

"It makes it a farce. For Northampton now to have to go away is unbelievable."

Despite Smith's verbal onslaught, Irish can still reflect on a season when they finished fourth in the Premiership, qualified for Europe's elite competition and won the Powergen Cup.

"We have probably exceeded where we thought that we would be. Before the start of the season, we would have taken all this with both hands," O'Shea added.

"But we don't want to be like Ipswich, qualifying for Europe this season and then being down the bottom next term.

"Everyone will be gunning for us, but we will be back with all guns blazing."