Hallam Amos scored one try and made another as Cardiff Blues beat Newcastle Falcons 33-20 in the hosts' first European game for almost two years.
The early try by Amos was cancelled out by George Wacokecoke soon after, but Sam Stuart then put the hosts ahead.
Two Jarrod Evans penalties and Tomos Williams' try set up by Amos soon after the break put the visitors in control as they scored 13 unanswered points.
Blues then got a late penalty try to seal a winning start to their campaign.
The Welsh side, who were forced into a couple of late pre-match changes, started the match stronger, forcing Newcastle back into their own 22.
But the Falcons repelled the Welsh attack a number of times before Wales international Amos, playing on the wing, dived into the left corner after a series of free-flowing passes in the 16th minute.
Newcastle, whose side bore little resemblance the the team that beat Wasps in their third successive Premiership win last week, grew into the half.
Three minutes after the Amos try, Wacokecoke drew the scores level from close range after hooker Jamie Blamire burst through the Blues defence with a 40-metre run.
Stuart scored five minutes before the break after Alex Tait ran back a clearing kick before good hands by Blamire set up the Falcons' scrum-half to go over in the corner.
But the Welsh side impressed with 16 unanswered points after the break when Williams cantered in under the posts after Amos impressively gathered his own high kick and fed his scrum-half in-between two Evans penalties.
Joel Hodgson's penalty finally got some points on the board for Newcastle with five minutes to go before Blues grabbed a late penalty try after Mark Wilson was sin-binned for pulling down a maul on his side's try line.
Newcastle director of rugby Dean Richards told BBC Radio Newcastle:
"The result is always important so you can't get away from the fact that we didn't quite get the win that we wanted.
"Having said that there's a lot of boys that were out there today that haven't played for a long time and that rustiness really showed.
"There's no escaping the fact that a lot of these boys hadn't played for a long time at that level and it probably showed.
"Had we done exactly what we did in the first half in the second half, as some of the lads said in the changing room, we'd have probably won the game."
Newcastle Falcons: Tait; Wacokecoke, Lucock, Matavesi, Arscott; Hodgson (capt), Stuart; Brocklebank, Blamire, Tampin, Barry, Montgomery, Farrar, Basham, Marshall.
Replacements: Maddison, Cooper, Ah You, Ransom, Wilson, Schreuder, Vuna, Connon.
Cardiff Blues: M Morgan; Millard, Smith, Thomas, Amos; Evans, T Williams; Thyer, Dacey, D Lewis, Davies, Hill (capt), Lewis-Hughes, Turnbull, Moore.
Replacements: E Lewis, Carré, Andrews, Murphy, Bradley, L Williams, Llewellyn, Grady,
Referee: Ludovic Cayre (France).