Ngwenya was offered a one-month trial at Saracens in England's Guinness Premiership by new coach Eddie Jones. However, he got a considerably better offer from Biarritz in France's Top 14, signing a two-year contract with them on 6 November 2007. Since 2007 Ngwenya has been a constant presence on the wing for Biarritz. Ngwenya scored 2 tries in the 2007-08 Heineken Cup. In the 2009–10 Heineken Cup he helped the club make their first final since the 2006, finishing tied for second in tries scored with 6. Ngwenya also had a stellar year in the 2009–10 Top 14 season, starting in 21 games and bagging 7 tries. In the 2010-11 Heineken Cup Ngwenya scored 5 tries, again tying for second. During the 2011-12 Top 14 season Ngwenya bagged five tries in the Top 14 and added 4 more in the Heineken Cup Ngwenya crossed the whitewash for Biarritz seven times in all competitions during both the 2012-13 and 2013-14 seasons.