Eric Elwood's side, who were already out of the running in Pool 1, have had a disappointing run of results of late and injuries to John Muldoon, Gavin Duffy, Ray Ofisa and Ezra Taylor have not helped.

They took a rejigged team to the south of France that included Amlin Challenge Cup debutants Shane Monahan and Eoin Griffin, with Fionn Carr being tested out at full-back.

A third European newcomer entered the fray for the province on the half hour mark, as the 20-year-old Shane Conneely replaced the injured Johnny O'Connor, Connacht's captain for the night.

The visitors hit the ground running in the opening quarter, taking a 13-3 lead on the back of a penalty try and eight points from the boot of Ian Keatley.

Referee Peter Allan awarded the penalty try in the 15th minute when the advancing Carr was taken out as he tried to collect Tuohy's chip kick. Keatley added the extras, but a second penalty from Bayonne scrum half Julien Audy closed the gap.

Keatley sandwiched another Audy penalty with two of his own, before Andrew Browne and Bayonne centre Sebastien Fauque were sin-binned, five minutes before half-time.

And although Keatley knocked over his fifth successful penalty shortly afterwards, Bayonne got right back in touch courtesy of a late converted try from centre Thibault Lacroix, who burst through a couple of tackles.

22-16 ahead at half-time, the westerners suffered an early setback in the second half when number 8 Marc Baget crossed for an unconverted score, taking advantage of some poor defending.

The momentum seemed to be with Bayonne now, but the introduction of Keith Matthews and Michael Swift added some steel to the visitors' efforts in defence and attack. A sixth Keatley penalty followed, giving Connacht a chance to breath at 25-21.

The sides adopted contrasting styles of play, with Connacht spreadint the ball wide and making use of every inch of the pitch. Bayonne, on the other hand, opted to keep it tight and try to make yardage through their maul.

In a strength-sapping half, Ronan Loughney, Adrian Flavin and recent recruit Rodney Ah You all made appearances in the front row for Connacht.

Then, Connacht suddenly found an extra gear in attack. They showed the sort of clinical edge that was missing in their interprovincial defeats to Munster and Leinster, and conjured a fantastic breakaway try.

A clever 73rd minute block by Frank Murphy and an acrobatic offload let the excellent Sean Cronin loose down the wing. The speedy hooker, who had to slot in at flanker, held the defender just long enough to release Tuohy for his first European score.

In the 77th minute, Carr put the icing on the cake for Connacht when he intercepted a pass and sprinted 60 metres for his fifth try of the current campaign.

Both conversions were missed, but they were not needed as Elwood's charges reaped the rewards of a huge collective effort.

Bayonne's woes were compounded when replacement Jean Jo Marmouyet was red carded in the dying minutes. Harlequins, who won 48-16 in Prato, now top the pool ahead of next weekend's crunch clash with Bayonne.