Five-eighth Byrne scored 13 points from the tee at Aviva Stadium and James Lowe dotted down in both halves as the defending champion stretched its winning run to four matches.

A penalty try for Leinster opened the scoring and although Tadhg Beirne and CJ Stander went over in the first half and Alby Mathewson added another 14 minutes from time, the Conference B leader was not to be denied another win.

Scarlets occupies second spot behind the holder after edging out its derby rival 20-17.

Quick-fire tries from Cory Allen and George North gave Ospreys a 12-10 advantage at the break after a fine early score from Johnny McNicholl.

Rhys Patchell's second half try and the boot of Leigh Halfpenny, who finished with 10 points, ensured Luke Morgan's try was in vain. 

Owen Lane helped himself to a double as Cardiff Blues also secured a derby win, seeing off Dragons 23-15, and Justin Forwood was sent off as Benetton Treviso beat Southern Kings 28-5.