Andy Farrell feels a “top drawer” defence is fuelling Ireland’s pursuit of successive Grand Slam titles as he turns his attention to nullifying England’s new blitz approach.

The reigning Guinness Six Nations champions limited Wales to a penalty try during Saturday’s 31-7 success in Dublin after nilling Italy 36-0 in round two on the back of beating France 38-17.

Ireland, who have scored 15 tries across the three bonus-points wins, travel to Twickenham on March 9 seeking to keep their championship clean sweep quest on track before hosting Scotland on the final weekend.

Ireland restricted Wales to a penalty try on Saturday afternoon in Dublin
Ireland restricted Wales to a penalty try on Saturday afternoon in Dublin (Brian Lawless/PA)

Head coach Farrell expects England to “go harder” as they get to grips with adopting an aggressive defensive strategy orchestrated by coach Felix Jones, who joined Steve Borthwick’s staff after helping South Africa retain the Rugby World Cup in the autumn.

“It’s the South African defence and I know that Felix will constantly try and put his stamp on implementing that,” said Farrell.

“There’s always going to be teething problems at the start but they’ll go harder because that’s their philosophy.

“Our defence is top drawer, there’s no doubt about that.

“It has been for quite some time now.

Former South Africa assistant coach Felix Jones was brought in by England following last year's World Cup
Former South Africa assistant coach Felix Jones was brought in by England following last year’s World Cup (Mike Egerton/PA)

“It was unbelievably fitting that we kept them (Wales) out because of the fight and want to be able to do that.

“I thought our defensive shape wasn’t very nice at times but our intent certainly on the line said a lot about how much they love defending for one another.”

Following two Twickenham defeats in the first year of the Farrell era, Ireland have beaten England four times in a row.

Borthwick’s men were minutes away from reaching the World Cup final in October but have made an unconvincing start to the championship with narrow wins over Italy and Wales followed by Saturday’s 30-21 Calcutta Cup loss in Scotland.

While Ireland will be favourites in south-west London, Farrell is aware matches can quickly change course after seeing Wales briefly gain the upper hand at the Aviva Stadium having trailed 17-0 at the break.

“Going to Twickenham, everyone knows how difficult a task that is,” he said.

“It’s not just as simple as saying we need to be better to win.

“Of course we always want to play better but the game is what it is, from minute one.

“For example, we’re winning the penalty count hands down at half-time (against Wales) and then all of a sudden within minutes of the second half, it has evened up.

“That could happen in two weeks’ time, role reversal. The game takes its own shape but there’s parts of our game we obviously need to improve.”