Leinster maintained their winning start to the BKT United Rugby Championship with a 24-6 win against the Emirates Lions, although the South Africans did keep Leo Cullen's side below four tries for the first time this season.Tries for Josh van der Flier and Caelan Doris saw Leinster keep the tourists at arm’s length for much of the contest at the Aviva Stadium, before a penalty try right on full-time put some gloss on the result.The South African side rarely threatened the Leinster line, but were organised and tough on the opposite side of the ball, repeatedly thwarting their hosts who spent the final 20 minutes chasing two scores which could have brought up a bonus-point.Sam Prendergast played 60 minutes, kicking two conversions and a penalty ahead of linking up with the Ireland squad next week, and while the out-half wasn't perfect, he continued to play with a sense of adventure, testing the corners and backfield with some innovative kicking.He linked up nicely on a number of occasions with his former Ireland Under-20 team-mate Hugh Cooney, who impressed in the centre on his home debut, but this was a game won in the forwards, with Doris, Van der Flier and Ryan Baird in particular carrying hard and getting their side over the gainline.RG Snyman needed less than a minute to have his first impact on the game, with his block-down on Morne van den Berg’s box-kick leading to a penalty under the posts, which Prendergast kicked to give his side an early 3-0 lead.Leinster enjoyed the bulk of the possession in the opening ten minutes, but weren't as clinical as they had been against Munster and Connacht in that early period.A series of excellent carries from Robbie Henshaw, Ryan Baird and Max Deegan provided the best