Fourteen-man Leinster produced an outstanding comeback to crush Ulster 38-29 and maintain their 100% United Rugby Championship record in a gripping derby in Dublin.

Tries from Rob Herring, Kieran Treadwell and Ethan McIlroy capped a dominant first-half display by the visitors.

Ronan Kelleher crossed to give the hosts hope just before the break, with a Garry Ringrose double and further tries from Andrew Porter and James Lowe making it a bonus-point win for Leinster, before Sam Carter grabbed a late consolation for Dan McFarland’s men.

Ulster were reduced to 13 men for a spell themselves with just less than 20 minutes remaining when James Hume and Nick Timoney were shown yellow cards, with the hosts taking full advantage.

Ross Byrne, fresh from his late kicking heroics for Ireland against Australia, was lethal with the boot for the URC leaders, clinically dispatching five conversions as well as an early penalty.

It is now nine wins from nine matches in this season’s URC for Leinster, with Saturday night’s victory stretching their lead at the top to nine points.

Defeat against their inter-provincial rivals will be difficult to take for Ulster who looked like they were in control of the game and on course for what would have been a statement win until that Kelleher try in first-half injury time shifted the momentum.

In a further blow to the Kingspan outfit, they ended the day in fourth place in the table, overtaken by Bulls and Stormers after having started the day in second.

Playing against a strong wind, Ulster’s stubborn defence was forcing mistakes from their hosts and, after Byrne and Cooney had slotted a penalty each, Healy got his red card on 21 minutes for a head-to-head collision with Tom Stewart with no mitigation.

Ulster let 19-point lead slip after strong start

McFarland’s men took immediate and full advantage, with Herring – just off the bench for Stewart – breaking away from an excellent maul following a line-out to cross for the opening try of the game.

More excellent aggression from Ulster’s pack set up Treadwell to brush aside Byrne while crossing on 29 minutes, with Ethan McIlroy running from halfway for the third try six minutes later after Stewart Moore had timed his pass to him perfectly.

John Cooney, who spoke during the week about the possibility of switching allegiances from Ireland to Scotland, hit two conversions and a penalty before having to go off with a head injury early in the second half.

Kelleher’s try was similar in build-up to Ulster’s first, with a kick to the corner being followed by an excellent line-out and maul before the hooker broke free to score.

A few errors from Ulster soon after the break set the tone for the rest of the half, with Hume getting his yellow card for a clash of heads with Ringrose just before the stand-in Leinster skipper got his first try on the hour.

A beautiful Ringrose dummy three minutes later saw him grab his second, which put them 24-22 ahead, with Timoney then having to go off for an infringement in the maul leading up to that score.

A Porter try, converted by Byrne, reinforced Leinster’s grip on the game and Lowe virtually walked across the line for their final try of the game on 76 minutes, leaving Carter to earn at least a try-bonus for Ulster in the final minute.

Captain Iain Henderson returned to the Ulster starting line-up, having come off the bench in the win over Zebres last week, but had to go off on 57 minutes to be replaced in the back row by for Duane Vermeulen.

McFarland will hope to have both men fully fit as his side face back-to-back European clashes, away to Sale next Saturday and at home to La Rochelle the following weekend.

Leinster: Keenan; O’Brien, Ringrose, Osborne, Lowe, Byrne, Gibson-Park; Healy, Kelleher, Ala’alatoa, Ryan, Jenkins, Baird, Van der Flier, Conan,

Replacements: Sheehan, Porter, Furlong, Molony, Doris, McCarthy, Tector, Turner.

Ulster: Lowry; McIlroy, Hume, McCloskey, Moore, Burns, Cooney; Warwick, Stewart, Moore, O’Connor, Treadwell, Henderson (capt), Rea, Timoney.

Replacements: Herring, Reid, O’Toole, Carter, Vermeulen, Doak, Stockdale, Rea.

Referee: Christophe Ridley