It took Leinster all their time to grind down defiant Ulster in the Heineken Champions Cup to set up a home quarter-final against Leicester Tigers next weekend.

The all-day rain made expansive movements difficult to execute. That was fine by Ulster, who immediately looked to slow the tempo through Billy Burns and Nathan Doak’s measured use of the boot.

Ross Byrne and Jamison Gibson-Park were not immune to putting the ball in the air to edge the battle for territory.

Once position was secured by Ulster, through a Hugo Keenan knock-on, Nick Timoney blasted off the back of a scrum to force a penalty at the ruck, scrum-half Doak slotting the lead points in the 10th minute.

The collective chase by the Blues of Byrne’s restart caused the visitors to go off their feet, Byrne levelling it from just 20-metres.

A booming boot from James Lowe turned defence into attack and Keenan recovered another high ball from Byrne only for Stuart McCloskey to capture a penalty at the breakdown.

Jordan Larmour spun away from defenders near the touchline. James Hume closed down Jimmy O’Brien in the outside channel and Michael Lowry claimed another bomb from Byrne as the chess moves continued.

A scrum penalty on halfway and an arrow of a touch finder by Byrne put Leinster in possession of a lineout deep inside the 22, the heavy men making metres, Ryan Baird muscling past Rory Sutherland for Byrne to make it 10-3 in the 21st minute.

Then, Jacob Stockdale’s terrific take of Lowry’s garryowen was undermined by McCloskey losing the ball forward.

The athleticism of Baird to catch Lowry in the open field and the pinpoint throwing of Dan Sheehan to Baird at the subsequent lineout drew a penalty.

The greasy conditions convinced Byrne to go for the posts from 45 metres for a two-score advantage in the 26th minute.

For the second time, Stockdale wanted a high ball more than those in the vicinity and Burns’ crossfield kick was taken in by Hume, who stepped inside Lowe for a fine try.

McCloskey’s side entry into a ruck was viewed as an infringement, Byrne pulling the shot left of the sticks.

David McCann’s side entry into a maul handed Leinster prime position, the ensuing maul splintering Ulster’s pack.

A quick tap penalty by Sheehan was almost translated into a try by Jack Conan, the number eight losing the ball inches from the line.

Leinster came back for the penalty advantage to be repelled by superb Ulster defence, Byrne eventually settling for three points.

Stockdale skewed his kick to invite Leinster forward for another attack, Gibson-Park’s angled ball to the corner forcing Ulster to complete a lineout to end the half 16-8 at the break.

That man Baird picked Lowry’s pocket at the breakdown and, once again, was the dominant target for Sheehan at the lineout.

Leinster moved through the phases without moving forward before Andrew Porter spilled the ball. They had to be more pragmatic.

Anyway, Gibson-Park was spotted on the wrong side of a ruck and Burns pumped the penalty inside the 22 where James Ryan promptly stole the lineout.

Hooker Sheehan rescued McCloskey’s grubber. Keenan collected another skyscraper. Lowry lost a high one and Ryan blocked John Cooney to keep Ulster pinned down.

Ryan slapped back an Ulster lineout. Josh van der Flier came onto it at pace. Conan knifed between defenders. Hume saw yellow for his actions at the ruck.

The lineout maul moved forward slowly to invite runners onto the ball, Gibson-Park finally benefiting from a pass by Robbie Henshaw to Byrne going to ground.

Quick as a flash, the scrum-half snapped it up and scooted to the posts. Byrne converted for 23-8 in the 55th minute.

The Ulster maul, a weapon all season, got going when Rob Herring connected with Harry Sheridan and the hooker was around in support to ground the ball for Cooney to convert in the 59th minute.

Byrne’s restart travelled all the way through the endzone to concede a scrum in midfield where the Leinster scrum turned on the power for a penalty.

An impressive attack involving forwards and backs concluded with Jimmy O’Brien being held up over the line by McCloskey.

They came back for a 5-metre penalty, Sheehan driving low, Scott Penny having a go and Andrew Porter making the difference with a little help from his friend Tadhg Furlong, Byrne’s conversion extending the lead to 30-15 in the 64th minute.

Yet again, Lowe launched from deep for Larmour to chase and get the block in, keeping Leinster in the right area.

Then, Sheridan was binned for a high tackle on Byrne amid a flurry of carries that tightened the grip on Ulster.

The Northern Province was not able to escape the strait-jacket that was Leinsters’ defence, rarely moving beyond the halfway line as time expired.