Diageo beat third-quarter sales forecasts on Wednesday, despite further weakness in North America that new CEO Dave Lewis said would be his biggest challenge to reviving growth at the world's top spirits maker. The Johnnie Walker whisky maker posted 0.3% organic growth in net sales, confounding forecasts for a 2.3% drop, helped by strong Guinness demand in Britain and Ireland and stocking up in Latin America and the Caribbean ahead of the soccer World Cup. The surprise beat gives Lewis an early boost. Shares in the British group were 5% higher at 0919 GMT. But performance in the U.S., Diageo's biggest market, remained a drag, with North American sales down 9.4%.