Leinster Rugby maintained their grip at the top of Conference A of the Guinness PRO14 with a fifth straight bonus-point return at Liberty Stadium on Sunday afternoon.

Ross Molony led Leinster out on the occasion of his 100th cap and the second row’s lineout calling was a foundation stone.

Prop Michael Milne started for the first time, on his 12th cap, and got into the game early, hitting it up for Harry Byrne to clear his lines.

However, Ospreys showed their intent when full-back Cai Evans countered and Will Griffiths shot through a gap in midfield from Josh Thomas’ exquisite flat pass.

Then, Dave Kearney had to be alert to snuff out the danger from Scott Williams’ grubber in behind to trigger Leinster’s ambition to spread the ball from deep.

The early signs were positive, Josh Murphy nicking an Ospreys lineout to further relieve pressure.

Referee Sam Grove-White spotted a Leinster scrum indiscretion to give the home side a prime attacking lineout which Adam Beard secured, the pack swarming around to force a penalty try in the ninth minute.

This was compounded by the binning of Scott Penny for his role in the concession of the automatic seven points and they gave away another penalty from the restart.

Increasingly, Jimmy O’Brien is becoming a go-to handler in the wide channels and his basic catch-pass put Rory O’Loughlin away up the left.

However, back-to-back knock-ons from full-back O’Brien and Scott Fardy facilitated an Ospreys scrum on the 22-metre line where Rhys Ruddock came to the rescue by clamping down for a penalty.

Out half Harry Byrne lashed out two immaculate touch finders to take Leinster deep inside enemy territory.

They were ruthless from there, Molony pulling down James Tracy’s throw, the maul moving forward for Milne and Scott Fardy to push close and for Tracy to drive over, Byrne converting from the left at the end of the first quarter.

The speed of ball was suddenly quicker and Leinster looked to move it until the ball went to ground, centre Williams hacking through and wing Mat Protheroe denied a try by the fine recovery skills of Jimmy O’Brien.

For the second time, the Ospreys lineout malfunctioned and Tracy tore away to establish the front foot. It was simply class from there on, Luke McGrath and Byrne letting the ball do the work, Rory O’Loughlin making the outside break, O’Brien acting as the link for Kearney to finish in style in the left corner.

Byrne converted from the touchline for 14-7 in the 27th minute and put real length into his clearance from the restart.

Captain Ruddock got off the back of a scrum for the sort of momentum that drew a penalty, Byrne missing to the left.

The Blues were beginning to turn the screw, Tommy O’Brien’s inside ball putting Kearney away up the middle. Tighthead Michael Bent kept the movement going and Byrne threw a pass for Penny to pick up the third try in the 34th minute.

The home side needed to respond. They looked likely until Fardy and Bent caused mayhem at a ruck to whittle out a penalty, preserving their 19-7 lead to the break.

The next score would be important, if not quite critical, Jimmy O’Brien continuing his trend of running the ball back.

Ruddock was seen to rip the ball from Williams when the Osprey had gone to ground. It gave Evans a shot at goal from 45 metres which was pulled left and wide.

The Leinster scrum looked a good deal more authoritative and the maul was dominant to enable Byrne guide his forwards into a promising position.

A set play sucked in defenders for Cian Kelleher to scoot into space, Kearney made ground down the tramline, Fardy found Ruddock with a fine offload only for one slip to lead to a knock-on.

A complete new Leinster front row entered the game and hooker Dan Sheehan connected with Molony for fast ball off the top of the lineout.

They probed patiently over and back until Williams went too high on Josh Murphy. Byrne rifled the penalty into the 22 as Dan Leavy replaced Murphy.

Sheehan and Molony were on the same page at the lineout and the pick-and-go was used to make headway.

When Tom Botha failed to roll away, Sheehan went quickly with Molony and Ruddock in support and Peter Dooley had enough momentum to make the line for the bonus point in the 58th minute. Byrne converted.

For once, the Leinster lineout did not execute. Shaun Venter was away to set up an attack.

But, the Irish province’s defence held well enough to force Venter to kick the ball into the hands of Jimmy O’Brien and, soon, Sheehan and Liam Turner were forcing Evans into a spill.

David Hawkshaw slotted in for Byrne at out-half and quickly settled in with a sweet pass and a solid kick to touch when Rhys Davies took out McGrath at a ruck.

Tommy O’Brien injured his leg in the next phase of play to force Leinster into a reshuffle, Hugh O’Sullivan coming in at full-back.

A strong Ospreys scrum and accurate lineout to the tail meant a heavy dose of close-in driving had to be defended vigilantly.

When that was achieved, Ospreys moved it left where Leinstermen Sheehan, Hawkshaw and McGrath shunted Luke Morgan into touch in a sign of their collective spirit.

Left wing Kearney had to be in position to shut down a dangerous attack on the right only for Jimmy O’Brien to overcook a kick.

The visitors were finding it difficult to escape, McGrath having to shake the ball from Protheroe for a scrum.

Ruddock was the first man on the scene when the Ospreys put the ball on the floor and Hawkshaw kicked long.

Still, O’Sullivan was called on to nail the lively Protheroe and Penny squeezed a penalty out of prop Botha to signal the end to the match with Leinster’s defence looking increasingly impenetrable