Ireland wrapped up their World Cup preparations in unconvincing fashion as they came from behind to beat Samoa.

While the Pacific Islanders stretched their lead to six, tries from Conor Murray and Rob Herring secured a record 13th straight Test win for Ireland.

But victory in Bayonne came at a price in the form of Cian Healy's injury.

The vastly experienced prop limped off in the first half with a suspected calf problem, handing Andy Farrell a last-minute selection dilemma before the head coach announces his 33-man World Cup squad on Sunday afternoon.

While Ireland continued their winning run to cling on to their world number one ranking, Farrell will almost certainly be concerned with a messy first-half display riddled with errors in admittedly testing conditions in south-west France.

While Ireland avoided a pre-tournament shock like England, who fell to Fiji earlier on Saturday, there is plenty for Farrell to ponder just a fortnight out from his side's World Cup opener against Romania on 9 September.

Healy injury concern for Ireland

Less than 24 hours out from his squad announcement, one of Farrell's main concerns was to get everyone back on the plane to Dublin in one piece.

However, having already lost wing Keith Earls to a "niggle" an hour before kick-off, allowing Jacob Stockdale to step in, a visibly uncomfortable Healy had to be helped off the field after just 21 minutes.

Healy - who was making his 125th appearance for Ireland - cut a dejected figure as he exited the field, immediately casting doubt over the 35-year-old prop's World Cup chances.

As Healy appeared pitchside on crutches and with a protective boot on his right leg, his team-mates continued to hobble around on the field in a performance that will have done little to reassure Farrell and his coaching staff before launching their World Cup bid in a fortnight.

Ireland did get off to a smooth enough start when O'Brien scored his first Test try in the ninth minute after Jack Crowley created the chance with a brilliant crossfield kick to Mack Hansen.

However, Ireland's error-strewn first-half display - which included 10 handling errors - was summed up when Stuart McCloskey's attempted pass to Robbie Henshaw cannoned off Paia'Aua, allowing the full-back to sprint clear and bring Samoa back into the game.

There was time for a couple of Irish handling errors before Samoa - who brought speed and enterprise to a scrappy game - won a penalty just outside the 22-metre line, with Sopoaga nailing his kick to give the Pacific Islanders a shock three-point lead at the break.

Herring makes big impact

While hooker Tom Stewart found the going tough in his first international start, his Ulster team-mate Herring made a significant impact off the bench.

Herring's impressive cameo was also well-timed considering the fitness troubles of hookers Dan Sheehan and Ronan Kelleher in recent weeks.

Indeed, with Ireland's line-out having deserted them in the first half, Herring's introduction immediately signalled a change of fortune as his throw found Ryan Baird to start a move which was finished by Murray dotting down Stockdale's clever kick into space.

As Samoa wilted in the closing stages, Ireland ensured they left Bayonne having completed a clean sweep of warm-up wins as Herring's try provided a satisfying conclusion to a stressful night for Farrell and his players.

Farrell will feel there is plenty to work on, but having come through three warm-up games with their winning run intact, attention turns to Dublin on Sunday as the Englishman finally unveils the 33 players he is bringing back to France on Thursday.

Line-ups

Ireland: O'Brien; Hansen, Henshaw, McCloskey, Stockdale; Crowley, Murray; Healy, Stewart, Bealham, Henderson (capt), Beirne, Baird, Van der Flier, Doris.

Replacements: Herring, Loughman, O'Toole, Ryan, O'Mahony, Casey, Byrne, Ringrose.

Samoa: D Paia'Aua; E Fidow, UJ Seuteni, T Manu, N Ah Wong; L Sopoaga, J Taumateine; James Lay, J Lam, P Alo-Emile, C Vui (co-capt), T McFarland, T Seu, F Lee, S Luatua.

Replacements: S Malolo, Jordan Lay, M Ala'alatoa (co-capt), M Fai'ilagi, SJ Taufua, E Enari, C Leali'ifano, N Foma'i.

Referee: Wayne Barnes (RFU)