LONDON - Swansea City produced a remarkable performance on their Europa League debut to thump Valencia 3-0 in Spain on Thursday, while Tottenham Hotspur also got their campaign off to a winning start.Swansea’s Group A trip to the Mestalla was, on paper, the standout of all those played in the Europa League on Thursday, but few could have imagined it would be so one-sided.A Swansea side coached by former Real Madrid and Barcelona star Michael Laudrup and featuring six Spaniards, including captain Angel Rangel, punished opponents who played 80 minutes with 10 men to run out thoroughly deserving winners.It was a stunning victory for a club that lost 8-0 to Monaco in their last European tie in the Cup Winners Cup in 1991. "It was a fantastic game,” Laudrup said afterwards. "Of course the red card was an influence – but we dominated from the first minute to the last."It could have been more than three and I’m very pleased to beat a club like Valencia. It was our fifth game in Europe – and we were facing a big team.”The win was only the second by a Welsh side against Spanish opponents in European competition, after Cardiff City beat Real Madrid 1-0 in the Cup Winners Cup quarterfinal, first leg, in March 1971. Cardiff lost 2-0 in the return.Meanwhile, Tottenham also won by a 3-0 margin, although their victory against Norwegian top-flight strugglers Tromso in Group K was a little less dramatic.A first-half brace by Jermain Defoe, which took him to within two goals of Spurs’ all-time leading European goalscorer Martin Chivers, effectively ended the contest inside half an hour.However, Danish midfielder Christian Eriksen, a recent signing from Ajax, added a superb third goal late on.Elsewhere, English FA Cup holders Wigan Athletic took time out from their bid to win promotion back to the Premier League to draw 0-0 away to Zulte Waregem in Belgium in Group D.In other games, Fiorentina of Italy were too strong for Pacos Ferreira of Portugal, running out 3-0 winners in Florence in Group E with Giuseppe Rossi among the scorers.