Newcastle Falcons had to come from behind at the break in the south of France to record their first victory in the European Challenge Cup as they beat Castres at the Stade Pierre-Antoine.
After trailing 10-9 at the break, Sam Stuart, Tom Arscott and Josh Basham scored second-half tries.
That was in response to two excellent tries by young winger Antoine Bouverand on his debut.
But the hosts did not score again until Vilimonu Botitu in the dying seconds.
That was converted by Bastien Bourgier to reduce the winning margin to nine points - but the previous French failings in front of the posts cost them any chance of a losing bonus point.
Newcastle, second only to champions Exeter in the Premiership after three straight wins, made eight changes for their trip to the Pyrenees from the side which lost to Cardiff Blues in last week's Challenge Cup opener.
After an early Brett Connon penalty, it looked ominous for the visitors when young winger Bouzerand scored twice inside three minutes down the right flank.
Both were created by full-back Clermont Clavieres - the second of them with a magnificent backhanded offload as he fell.
But both conversions from out wide were crucially missed to leave the Falcons only seven points down - and two Connon penalties inside three minutes just before the break got the Falcons back within reach.
Newcastle then turned it round by scoring two tries inside 11 minutes - the first for scrum-half Stuart, his second in as many games, and then another for full-back Arscott.
Basham got in on the act late on, Connon landing the hardest of his three conversion attempts to add to his three first-half penalties.
Botitu popped up to have the last word, but Dean Richards' men were still able to take victory with a comfortable buffer.
Castres: Clavieres; Guillemin, Botitu, Vialelle (capt), Bouzerand; Le Brun, Fernandez; De Benedittis, Firmin, Tierney, Meka, Clerc, Onambele, Kornath, Hermet
Replacements: Colonna, Decaux, Vidal, Olivier, Cope, Bourgier, Dupont, Amans
Newcastle: Arscott; Kerr, Lucock, Matavesi, Vuna; Connon, Stuart; Cooper, Maddison, Ah You, Farrar, Barry, Marshall, Wilson (capt), Basham
Replacements: Blamire, Brocklebank, Daniels, Lockwood, van der Walt, Pascoe, Haydon-Wood, Obonna
Referee: Craig Evans (WRU)
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