Leinster were far from at their best but did enough to pick up another Heineken Champions Cup bonus-point win as they saw off an understrength Northampton at the RDS.

It was a tighter contest than expected in the first half, with tries from Josh Murphy, Cian Healy and Dave Kearney giving injury-hit Leinster a 22-14 interval lead.

Fraser Dingwall and Champions Cup debutant Tom James hit back for Saints, who fielded a much-changed side following last week's home loss to Bordeaux.

Jamison Gibson-Park and Nick Isiekwe swapped early second-half tries, leaving out-half Ross Byrne to kick Leinster home with two closing penalties.

Despite losing Caelan Doris and Harry Byrne to late injuries, the disruption made little initial impact on the hosts as flanker Murphy, a first-time starter in Europe, crashed over in the second minute after a break by Garry Ringrose.

James Ryan charges down Tom James' clearing kick

Byrne’s older brother Ross converted but was met by a meaty tackle from Dingwall soon after, as the resulting turnover penalty relieved some pressure on Saints.

A well-supported Healy burrowed over on the 15-minute mark, making up for an earlier knock-on close to the tryline. Byrne converted for 14-0.

However, the departure of a concussed Jimmy O’Brien meant further action on the Irish province’s bench and Northampton were able to take advantage.

Dingwall took a lovely line onto a James pass to score underneath the posts, with his centre partner Rory Hutchinson converting.

Byrne responded with a 27th-minute penalty for a ten-point lead, only for scrum-half James to profit from a strong Northampton scrum, reaching over past two covering defenders.

Leinster regained their composure late on, though, as Gibson-Park used a penalty advantage to fling a pass wide and put Kearney over in the left corner, despite Ryan Olowofela’s attempts to intercept.

Jamison Gibson-Park grabs Leinster's bonus-point try

The second half was only two minutes old when Gibson-Park sauntered in under the posts, profiting from an advancing scrum and exposing some poor defending from stand-in fly-half George Furbank.

After Byrne added the extras, Gibson-Park quickly handed back five points when his kick was charged down by loan signing Isiekwe, who collected for his first European try. Hutchinson missed the difficult conversion.

A sudden rain shower made for a scrappy third quarter, with Northampton having plenty of possession, their best move being a neat chip-and-regather by Tom Collins. Those result-sealing penalties from Byrne came in the 60th and 71st minutes.

It was Northampton's 13th straight defeat in all competitions and the citing commissioner may have a closer look at a Tom Wood clearout where his shoulder made contact with Josh Van Der Flier’s head.