Ulster are the new leaders of the Magners League after half-backs Ian Humphreys and Isaac Boss scored 16 points between them to down European champions Leinster in Saturday’s interprovincial derby at Ravenhill.

Ulster’s acting captain Chris Henry proclaimed it the best victory yet for Brian McLaughlin’s side as they held out for a narrow but deserved two-point win over provincial rivals Leinster at a wet and windy Ravenhill.

Following their European defeat last weekend in Edinburgh, Ulster bounced back strongly to claim top spot in the Magners League, with the Irish management team, including head coach Declan Kidney, interested spectators.

The bulk of the 11,523 attendance certainly left the Belfast venue much the happier as Leinster failed to build a healthy lead during a wind-assisted first half and a late flourish, which included a converted try from replacement Luke Fitzgerald, gave them nothing more than a losing bonus point.

In what was only Ulster’s second win over Leinster at Ravenhill since 2000, a crucial second half try from man-of-the-match Isaac Boss paved the way for victory for an Ulster side that played the conditions better.

This result was a further indication of Ulster’s dominance over their provincial brethren in recent meetings, with this being their fourth win in their last five games against Irish opposition.

It was a typically dogged game at the rain-soaked Belfast ground, defences were on top in the opening stages and Leinster out-half Shaun Berne failed to convert a trio of penalty chances in a extremely tricky, gusting wind.

Berne found the wrong side of the posts in the 9th, 20th and 23rd minutes on a difficult night for goalkicking.

The scoring drought was eventually broken in the 36th minute. Ulster showed some great continuity through their forwards before Leinster were penalised in front of their posts and hooker Bernard Jackman was sent to the sin-bin for infringing at the ruck. Ian Humphreys landed the resulting penalty kick for a 3-0 lead.

But with Ulster flanker Tamaiti Horua sin-binned approaching the interval, Leinster seized control.

With stand-in skipper Brian O’Driscoll pulling the strings, they got a much-needed break when Australian Berne made it over in the right corner for an injury-time try after some quick thinking from Jamie Heaslip and a final pass from O’Driscoll.

Following an excellent conversion from wide out, Berne pushed the visitors 7-3 clear for the interval.

McLaughlin’s half-time words did the trick and Ulster came thundering back on the restart. Humphreys nailed a 46th minute penalty to reduce the arrears to a point and then UIster’s juices really started to flow.

Covering close to 50 metres, Boss sailed through for a try on the blindside after Henry had done very well to secure turnover ball. Humphreys’ successful conversion made it 13-7.

Hit with an Ulster onslaught at the beginning of the second period, Leinster dug deep and O’Driscoll and company pushed hard to overcome the six-point deficit.

There were changes aplenty to the visiting outfit with Fitzgerald and Sexton coming on to inject some spark into the back play.

Isa Nacewa also rose to the challenge on the left wing and sent the reasonably large Leinster travelling support into raptures when he brought Humphreys to ground in the 58th minute.

Rob Kearney and O’Driscoll combined well in the 60th minute to almost tee up a try, but the move broke down after Sexton fumbled an inside pass from O’Driscoll with the line in his sights.

A third Humphreys penalty, eight minutes from time, added some cushion for Ulster and Fitzgerald’s last-gasp try, set up by Nacewa’s clever chip through and converted by replacement Jonathan Sexton, was the final act of a real battle royale in Belfast.

Delighted with his side’s fourth win of the league run, Ulster boss Brian McLaughlin said: "It was a difficult night to play rugby. But we fought hard and did what we had to do.

"All credit to the lads, they stuck at it and grabbed a smashing try just after half-time.

"We handled the conditions extremely well, and it was a case of when we got into their half we took the points. We came off a defeat last week against Edinburgh and we were bitterly disappointed.

"It was a great fillip to have the European champions coming up to us this weekend. We racked it up during the week and all credit to the players they reacted in the right way."

His Leinster counterpart Michael Cheika admitted afterwards: "I think we were too patchy, though I felt that we played well in certain stages of the game. We didn’t manage the first half well and that cost us.

"Tonight we worked hard but we weren’t smart enough and gave them yards when we shouldn’t have.

"Having made a few changes to the team it wasn’t going to be easy for them to get consistency.

"The important thing is that we get back on the road again against Cardiff in front of our home crowd next week."