Early tries from Rugby World Cup debutant Fergus McFadden and Sean O'Brien set Ireland on their way in wet conditions, before a late flourish gave them a 36-0 lead at the interval.

Isaac Boss, Keith Earls and Andrew Trimble all touched down in a profitable four-minute spell before referee Craig Joubert's half-time whistle. Earls completed his brace, but Russia then burst into life with two well-taken tries.

Former Leinster and Ireland underage player Vasily Artemyev and Denis Simplikevich showed off their finishing skills as the Bears reduced the arrears to 43-12.

But Ireland, who sent on every replacement bar Rory Best, added three more tries in the final quarter from Rob Kearney, replacement Shane Jennings and Tony Buckley.

Declan Kidney's men turned in a composed, economical display which contained some flashes of brilliance. Having established early dominance, they had the bonus point in the bag by the 38th minute.

Notably, it is only the second occasion that Ireland have won three pool matches in-a-row - they beat Romania, Namibia and Argentina at the 2003 tournament.

Today's 50-point success has them three points clear at the top of the table ahead of their final Pool C game against Italy next Sunday.

MasterCard man-of-the-match Ronan O'Gara pinned the Russians back with some clever kicks early on, with crisp passing from Boss and strong running from O'Brien and Sean Cronin putting Ireland into try-scoring range.

They settled for a sixth minute penalty from O'Gara, who tapped down as the rain came down. Moments later, Jamie Heaslip linked with Trimble after a powerful surge from the number 8, and in the ensuing phase an offside and deliberate knock on from Russian out-half Konstantin Rachkov resulted in him being sin-binned.

Ireland strung together two tries while Rachkov was off the pitch. O'Gara's brilliantly weighted dink over the Russian defence saw McFadden slide over for the opening try, which the Corkman converted from the right.

Ireland were back on the offensive in no time. They showed good control and distribution of the greasy ball as Earls cut through and offloaded for Cronin to set up a promising ruck position. With an overlap created on the right, Boss put O'Brien through a weak challenge and over for a seven-pointer.

At the midpoint of the half, Russia got their first chance to stretch their legs. Turnover ball led to Andrey Kuzin sprinting towards the Irish 22, number 8 Victor Gresev also threatened on the left before O'Brien gave away a penalty.

The resulting lineout throw was crooked however, and Boss soon dispatched the ball into touch. Ireland defended with a degree of comfort until the impressive Donnacha Ryan won a penalty at the breakdown and a barnstorming run from Cian Healy ignited the attack again.

O'Gara's cross-field kick for Trimble was gathered in by Vladimir Ostrushko, but the Russian winger's hopes of breaking away down the right were crushed by some organised Irish defence.

O'Gara and Paddy Wallace were distributing well and O'Brien drew in a number of Russian defenders each time he ran hard with ball in hand. Captain Leo Cullen and the forwards also supplied a solid platform from the set piece and breakdown.

Ireland raised the tempo again before the break, Boss placing the ball onto the pad of the right hand post for a converted try which required confirmation from television match official Giulio De Santis.

It was a proud moment for the scrum half who was born only 30 kilometres away in Tokoroa. Trimble increased his influence with a swift break and flat pass which sent Earls away and in at the left corner. The centre did well to keep his body in play, under pressure from the covering Simplikevich.

O'Gara added the extras to the bonus point try but was denied by the left upright when attempting to convert Trimble's 40th-minute effort.

Trimble showed excellent awareness as, after Andrey Garbuzov had illegally knocked the ball back on the Russian side, the big winger was on hand to hack the ball forward and touch down to the left of the posts.

Ireland had some defensive duties to deal with, early in the second period, and the advancing Trimble was reeled back for a forward pass from Kearney.

The Ulsterman then put in a huge hit on Sergey Popov as Russia remained on the attack, but the resulting ruck gave Ireland a penalty and good foraging on the deck from Cronin and Cullen supplied clean ball for Boss.

Earls then spotted a sliver of space in the middle, between two Russian forwards, to blast away and race in behind the posts from 30 metres out.

O'Gara's conversion brought the 50-point mark into range and the Irish management decided to make some tweaks, with Denis Leamy's introduction for Donncha O'Callaghan seeing Ryan move into the second row and Earls' withdrawal brought McFadden into the centre and Geordan Murphy onto the wing.

Russia responded with a terrific try from their full-back Artemyev. The 50th minute attack was sparked by Alexander Yanyushkin who broke to the right from the base of a scrum, linking with Artemyev who picked a great angle to get past O'Brien and Heaslip and his quick feet took him past Kearney and over the whitewash.

Rachkov tagged on the conversion and the Bears conjured up another cracking score on the hour mark.

Vladimir Ostrushko did most of the hard work, breaking through the Irish defensive line and passing for the 20-year-old Simplikevich to avoid the grasp of McFadden and Trimble and crash over past Wallace's despairing tackle.

With more fresh legs coming onto the pitch, Ireland reasserted themselves. Ryan and Wallace were central to a brilliant piece of interplay and when Trimble looped a long delivery out to the left, Heaslip's short pass put Kearney over for Ireland's seventh try.

O'Gara's pinpoint conversion made it 50-12 and the tiring Russians conceded two more tries. Jennings picked from a ruck and dived over for his first international try, with replacement Jonathan Sexton converting.

Some neat passing and intelligent lines of attack preceded Buckley's second career try. The big prop was simply unstoppable on a bulldozing run from seven metres out.

The nine-try tally was just one short of Ireland's World Cup record haul - they scored ten when beating Namibia 64-7 at the 2003 World Cup.

But there was another personal milestone for Ronan O'Gara. He is now Ireland's record World Cup points scorer with 72 points - surpassing both Ralph Keyes (68) and David Humphreys (70).