Leinster coach Joe Schmidt believes the Magners League play-off race has narrowed down to five clubs chasing three semi-final places as number one seeds-elect Munster are too far clear of the chasing pack.
The Blues temporarily moved into second place with a workmanlike 26-15 win over the Scarlets at the RDS last night, ahead of home matches for leaders Munster and defending champions the Ospreys this evening.
"The Welsh teams are going to be a very dangerous proposition because the three Irish teams, Munster, Ulster and ourselves, are all involved in (European) quarter-finals," Schmidt said.
"Even the second home slot is going to be difficult to get because the Scarlets, Cardiff and the Ospreys don't have anything else to play for. It is the Magners League for them.
"We are not distracted by the Heineken Cup. We are delighted to be where we are.
"But, at the same time, those teams will have time off to freshen themselves up and make a charge."
Last night, the Scarlets spoiled their confident, bright beginning by wilting in the face of Leinster's first intrusion into their half.
A long, low trajectory kick from Isa Nacewa gave the home side position. Simple, textbook passing from Fergus McFadden and Nacewa put Niall Morris one-on-one with Rhys Priestland.
The Scarlets' out-half made an embarrassing pawing effort at the tackle and Morris wheeled around the outside for a soft try, converted confidently from wide on the right by Jonathan Sexton in the ninth minute.
On their next visit, the tempo was building until Josh Turnbull made one of those incomprehensible fouls at the breakdown. Sexton spanked it through for three more points.
When Sexton stepped up offside from a set-piece play, Priestland struck his first penalty, from his third attempt at the posts, to reduce the deficit to 10-3 in the 28th minute.
It stayed that way until the break, largely because Andy MacPherson abruptly called a halt to a Leinster maul that was on the move and in control no more than 10 metres from the Scarlets' line.
Scarlets coach Nigel Davies would have reminded his players they were one missed tackle away from going in on equal terms at the break. There was little or nothing in it.
Thereafter, it was clear Leinster were looking to lift the tempo. Immediately, scrum-half Isaac Boss connected cleverly with Dominic Ryan around the side of a ruck for a gain of 30m.
Number eight Rhys Ruddock stayed on his feet to further eat into the Scarlets' defence. Eventually, Turnbull flopped over on the wrong side to allow Sexton to make it a two-score game in the 43rd minute.
Hooker Richardt Strauss, lock Devin Toner and Boss were the catalysts for a slick raid down the left that put the Scarlets in a spin. The penalty followed and Sexton stretched Leinster's lead by another three points.
Openside Turnbull refused to take heed of the rules of the breakdown, giving away yet another penalty for Sexton to smack the ball between the sticks to lead 19-3 in the 54th minute.
Out of nowhere, the Scarlets put phases together, stretching Leinster left and right before tighthead Rhys Thomas took the ball through the middle for a well-crafted try. Priestland converted from a difficult angle.
The raft of penalties was working against the Scarlets. Centre Gareth Maule was binned for not rolling away at a ruck. Leinster opted for a scrum instead of a penalty. They marched forward and Boss's strength was too much close to the whitewash.
That was game over. But the Welsh club gathered themselves for one last drive. They held their depth well in attack to put replacement wing Nick Reynolds outside the Leinster defence.