Leinster make Saints suffer again at the Aviva Stadium
Saints were made to suffer again by Leinster as the Irish giants claimed a crushing 50-21 Champions Cup win at the Aviva Stadium on Saturday evening.
Leo Cullen's side won 43-16 at Franklin's Gardens last weekend and they were in similarly ruthless form as they ran in another seven tries, taking their tally to 14 in two matches against Saints.
It was another sobering Dublin experience for the black, green and gold following the 2016 encounter which was won 60-13 by Leinster.
But Saints, depleted by injuries and the need to rest some weary bodies, kept fighting until the end as they frantically searched for the fourth score that would bring them a bonus point.
It wasn't to be though as Leinster allied ferocious defence with razor-sharp attack to stop Saints taking anything from their difficult December double-header.
Chris Boyd's men are now likely to need maximum points from their final two Pool 1 matches to stand any chance of making the last eight.
They had headed to Dublin hoping to repeat the 2013 win at the Aviva Stadium, but they made the worst possible start as Andy Symons saw his kick charged down and Garry Ringrose gathered to score.
Ross Byrne, in for the injured Jonny Sexton, landed the conversion with aplomb from the touchline to compound Saints' misery.
It got worse for Saints soon after as Leinster shifted the ball at real speed before Ringrose charged in for his second.
Byrne easily converted and it was 14-0, with Saints desperate to summon a response.
Api Ratuniyarawa knocked on in the Leinster 22 as his side finally got some territory and possession, and Leinster were soon back at the Northampton door.
Tom Wood, who led Saints out on his 200th appearance for the club, was punished for a high tackle and Byrne did the business to make it 17-0 inside 12 minutes.
Saints needed a shot in the arm and after Biggar made a break, a penalty was won and went to the corner.
Saints stayed patient and eventually a lovely offload from centre Symons released Biggar to score under the posts.
Biggar added the conversion, but the hope was shortlived as Ahsee Tuala was yellow carded for a shirt pull off the ball on the menacing James Lowe.
And Leinster took immediate advantage as Tadhg Furlong rumbled over from the dominant lineout drive.
Byrne converted and it was 24-7 after just 22 minutes with Leinster already just a try away from bagging the bonus point.
And it got worse for Saints as Wood was next to be sin-binned with his team giving away penalty after penalty.
But they somehow held out to win the ball back and even won a penalty at a scrum with Taqele Naiyaravoro at No.8.
However, Leinster would get their bonus point before the break as Dave Kearney skipped past Ollie Sleightholme out wide and cruised in for the score.
Byrne converted to make it 31-7, but Saints were able to respond before the break as Lewis Ludlam channelled his inner Jamie Elliott and broke from an intercept.
It led to the ball being send from left to right for Tuala to release Sleightholme for the score.
Biggar converted to cut the gap to 17 points and Saints were halfway to a try bonus point that could have proved so crucial in the race to make the quarter-finals.
Saints showed some ambition at the start of the second half but after the ball was spilled, the electric Jordan Larmour carried Leinster forward and Lowe eventually latched on to a grubber to score.
Byrne missed the conversion but it wasn't going to matter as the pattern of the game continued with Saints making errors and Leinster taking advantage.
Ringrose thought he'd scored soon but he was held up superbly by Sleightholme.
However, it wasn't long before the Ireland centre did get his hat-trick as the ball spilled into his path and he darted over the line.
Ciaran Frawley converted and he was about to again soon after as Dave Kearney raced away to dot down, but the TMO spotted an early hit on Biggar and gave Saints a penalty in the Leinster 22.
Saints kept fighting but they were being met with fierce resistance at every turn as the blue wall stood tall.
But Tuala found a way through, picking up at the breakdown and sprinting into space before diving over for his team's third try.
Biggar kicked and Saints were now one score from a bonus point with more than 20 minutes to go.
However, Leinster were next to score as No.8 Caelan Doris showed his opportunism to score a try similar to the one Tuala had claimed just before.
Frawley converted to bring up the half-century for the home side, bringing a big roar from the Aviva Stadium crowd.
Saints still had 13 minutes to find the try they desperately wanted but they couldn't make the territory they had count as Leinster held out with some more impressive defence.
Leinster: Larmour; D Kearney, Ringrose, Henshaw (R Kearney 61), Lowe; R Byrne (Frawley 48), McGrath (Gibson-Park 61); Healy (E Byrne 14), Tracy (B Byrne 54), Furlong (Porter 51); Fardy (c) (Toner 69), Ryan; Ruddock, van der Flier (Deegan 61), Doris.
Saints: Tuala; Sleightholme, Proctor, Symons (Dingwall 48), Naiyaravoro; Biggar (Grayson 62), Tupai (J Mitchell 60); van Wyk (Waller 58), van Vuuren (Matavesi 50), Hill (Painter 66); Ratuniyarawa, Coles (Bean 4) (Tonks 71); Wood (c), Gibson, Ludlam.
Referee: Dan Adamson