Nigel Carolan’s side killed off France’s second half revival with a closing 74th-minute penalty from stellar out-half Bill Johnston who had a 100% return off the tee for a 12-point haul.

Three first half tries from Tadgh McElroy, man-of-the-match Tommy O’Brien and Oisin Dowling had the hosts leading 21-10 at half-time, with Faraj Fartass responding for the French.

Johnston book-ended an attritional second half with two crucial penalties, and although the visitors did set up a grandstand finish with Fartass’ second effort and a penalty try, Carolan’s charges stayed in front to seal their third 2017 win and make it a record-equalling six successive Six Nations victories for Ireland at this age-grade.

The visitors got off to an electric start but had no points to show for it, their livewire scrum half Arthur Retiere twice going close from his own chip and then a quick tap.

A head clash between Ciaran Frawley and Calvin Nash saw the latter forced off permanently - the third Ireland U-20 captain to be sidelined in the current campaign - but two strong scrums from the home pack, combined with French indiscipline, saw Ireland move out of their half.

Nash’s replacement Alex McHenry blocked a kick to give Ireland their first serious attacking opportunity and they took full advantage, excellent winger Jordan Larmour weaving up close to the line before hooker McElroy barged over from a metre out.

Johnston converted for good measure and Larmour popped up in a free-flowing move soon after, while Ireland almost ended the first quarter with another try. William Iraguha had to react quickly to bring down McElroy after great combination work from the lineout by Jack Regan, Jonny Stewart and McElroy.

Good French build-up play was rewarded with a penalty from Romain Ntamack, but Ireland cancelled those three points out with a neatly-taken seven-pointer from centre O’Brien who was fed off a scrum and gathered his own grubber kick to dot down.

Ireland blew another try-scoring opportunity when Larmour’s pass to McElroy was ruled forward with the whitewash in his sights. There was some great work beforehand from out-half Johnston - both with his boot and with ball in hand in front of the posts.

However, second row Dowling showed his alertness to get his hand on a ball that had gone over the French line and force a try which TMO Stuart Terheege confirmed. Johnston converted for a 21-3 scoreline.

France, though, succeeded in hitting back before half-time with numbers wide on the left creating a simple finish for winger Fartass. Ntamack’s conversion went over with the aid of the post and Ireland had to defend smartly to avoid conceding again just before the break.

Larmour increased his influence on the resumption, his strong running causing the French defence plenty of headaches, and Johnston followed up with a well-struck penalty for 24-10.

Ireland’s structures and character was tested once more as full-back Lyttle went out for a HIA and Marcus Rea had to be replaced. French dangerman Iraguha showed his ability in defence when he hoovered up a tricky grubber kick, and his wing colleague Fartass was soon charging down the left wing.

Ireland could not hold out on the hour mark when their defence was sucked in during a bout of French pressure - aided by their strong bench - and Fartass did well to finish past Ciaran Frawley for a try by the left corner flag.

Ntamack missed the difficult conversion and following a speedy burst by Iraguha into the Irish 22, replacement Sean Masterson saw yellow for an obvious ruck offence. Solid tighthead Charlie Connolly’s departure and Masterson’s sin-binning left the Irish scrum under pressure and three successive set piece penalties saw referee Tom Foley award a 72nd-minute penalty try to les Bleuets.

Importantly, Ireland gave themselves a five-point cushion just a couple of minutes later. A terrific kick from Johnston forced Iraguha to play the ball in his 22 and a subsequent offside allowed the Munster Academy starlet to send over his second successful penalty.

Another probing kick, this time from Larmour, gained vital territory for Ireland in the dying minutes and the forwards, including prop Joey Conway and number 8 Caelan Doris who both put in impressive shifts, held possession right to the final whistle as Carolan’s youngsters kept hold of second place (behind England) in the Championship table.

TIME LINE: 14 minutes - Ireland try: Tadgh McElroy - 5-0; conversion: Bill Johnston - 7-0; 23 mins - France penalty: Romain Ntamack - 7-3; 24 mins - Ireland try: Tommy O’Brien - 12-3; conversion: Bill Johnston - 14-3; 30 mins - Ireland try: Oisin Dowling - 19-3; conversion: Bill Johnston - 21-3; 36 mins - France try: Faraj Fartass - 21-8; conversion: Romain Ntamack - 21-10; Half-time - Ireland 21 France 10; 45 mins - Ireland penalty: Bill Johnston - 24-10; 61 mins - France try: Faraj Fartass - 24-15; conversion: missed by Romain Ntamack - 24-15; 66 mins - Ireland yellow card: Sean Masterson; 71 mins - France try: Penalty try - 24-20; conversion: Romain Ntamack - 24-22; 74 mins - Ireland penalty: Bill Johnston - 27-22; Full-time - Ireland 27 France 22

Scorers:

Ireland U-20s: Tries: Tadgh McElroy, Tommy O’Brien, Oisin Dowling; Cons: Bill Johnston 3; Pens: Bill Johnston 2

France U-20s: Tries: Faraj Fartass 2, Penalty try; Cons: Romain Ntamack 2; Pen: Romain Ntamack

HT: Ireland U-20s 21 France U-20s 10

IRELAND U-20: Rob Lyttle (Queen's University/Ulster); Jordan Larmour (St. Mary's College/Leinster), Tommy O'Brien (UCD/Leinster), Ciaran Frawley (UCD/Leinster), Calvin Nash (Young Munster/Munster) (capt); Bill Johnston (Garryowen/Munster), Jonny Stewart (Queen's University/Ulster); Joey Conway (UL Bohemians/Munster), Tadgh McElroy (Lansdowne/Leinster), Charlie Connolly (Dublin University/Leinster), Jack Regan (UCD/Leinster), Oisin Dowling (Lansdowne/Leinster), Marcus Rea (Queen's University/Ulster), Paul Boyle (Lansdowne/Leinster), Caelan Doris (St. Mary's College/Leinster).

Replacements: Ronan Kelleher (UCD/Leinster), Rory Mulvihill (UCD/Leinster), Peter Cooper (Belfast Harlequins/Ulster), Gavin Coombes (Young Munster/Munster), Sean Masterson (Corinthians/Connacht), Jack Lyons (Young Munster/Munster), Conor Fitzgerald (Shannon/Munster), Alex McHenry (Cork Constitution/Munster).

FRANCE U-20: Romain Buros (Pau); Faraj Fartass (Stade Francais), Pierre-Louis Barassi (Lyon), Theo Dachary (Biarritz Olympique), William Iraguha (Massy Essonne); Romain Ntamack (Toulouse), Arthur Retiere (La Rochelle); Kevin Tougne (Perpignan), Etienne Fourcade (Grenoble), Thomas Laclayat (Oyonnax), Florian Verhaeghe (Toulouse) (capt), Mickael Capelli (Grenoble), Dylan Cretin (Lyon), Julien Ruaud (Clermont Auvergne), Alexandre Roumat (Biarritz Olympique).

Replacements: Leo Aouf (La Rochelle), Florian Dufour (Agen), Georges Henri Colombe (Racing 92), Killian Geraci (Grenoble), Cameron Woki (Massy Essonne), Baptiste Couilloud (Lyon), Anthony Fuertes (La Rochelle), Theo Millet (Stade Francais).

Referee: Tom Foley (England)