Sexton opened the scoring at Rodney Parade with an early penalty before Adam Hughes put the Welsh team in front with the game’s opening try.

Aled Brew made a thumping tackle on Luke Fitzgerald which allowed Wayne Evans to pass the ball to Hughes who sprinted 60 metres to score.

Jason Tovey added the conversion and another penalty before Isaac Boss grabbed Leinster’s first try.

The New Zealand-born Irish international grabbed the ball at a ruck and touched down to bring Leinster level.

Tovey slotted another penalty to put the Dragons 13-10 up at the break and Hughes could have stretched their lead when he was stopped just short of the try-line at the start of the second half.

Sexton then gave Leinster back the lead with two penalties as Brew was sent to the sin bin in what proved to be the turning point in the match.

Tovey produced a great last-gasp tackle to deny Fitzgeral a try, but the Dragons eventually crumbled as Andy MacPherson awarded Leinster a penalty try after a collapsed scrum.

Sexton added another penalty to move his side ten points clear and though the Dragons fought hard, it was Leinster who came closest to scoring again as Isa Nacewa was denied late on.