Maintaining the momentum from their upset victory over Australia last week, the Irish scored three tries at the end of each half to claim a bonus-point victory over a Russia team playing its third game in 11 days.
Flyhalf Ronan O'Gara was outstanding for Ireland, kicking seven from eight with the boot and marshalling a backline which had been overhauled from last week's triumph to help ensure Ireland would go into their final pool game against Italy next weekend with three wins from three.
"A few guys got an opportunity this week to back up the performances of last weekend," said Ireland captain Leo Cullen. "It was important to continue the momentum. We will take the win and move on."
Russia, who have now lost all three matches on their World Cup debut, battled manfully to stem the green tide and got reward for their efforts with second half tries from fullback Vasily Artemyev and winger Denis Simplikevich.
"We didn't play very well in the first half," said Russia coach Nikolay Nerush.
"But we played better in the second half and the game was more interesting. So we have a feeling of something unfinished."
The match started in a brief period of sunshine between rain showers and O'Gara had already converted a penalty when his opposite number Konstantin Rachkov was sin-binned in the eighth minute for a deliberate knock on.
Ireland took full advantage of their numerical superiority with winger McFadden sliding across the wet turf to gather O'Gara's cross-kick in the 10th minute before flanker Sean O'Brien crashed through the defence for a second try three minutes later.
The Irish attack then stalled, however, and the attack-minded Russians carved out a few chances of their own but the three tries in three minutes at the end of the first half effectively ended the match as a contest.
New Zealand-born scrumhalf Isaac Boss inched over from close range for the first, livewire winger Andrew Trimble's break put centre Keith Earls in for the second and Trimble added the third himself on the stroke of halftime.
Earls carved his way through the defence to cross for his second eight minutes into the second half and, when O'Gara kicked his fifth conversion, the Irish were leading 43-0.
The Russians finally got some reward for their brave performance two minutes later when fullback Artemyev, who represented Ireland at schoolboy level, scythed through the Irish defence to touch down.
The noisy Russian element in the largely green-clad crowd of 25,000 were back on their feet nine minutes later when winger Simplikevich bulldozed his way across the try line in the corner.
The fightback was short-lived, however, and Ireland hammered home their superiority with tries in the last 15 minutes from Rob Kearney, replacement flanker Shane Jennings and prop Tony Buckley, the heaviest player at the tournament at 137kg.
"We had hot and cold patches," said Ireland coach Declan Kidney. "We probably fell off in the middle of both halves ... There were plenty of good things but bits to work on too."
6’ O’Gara penalty: Ireland 3-0
10’ McFadden try: Ireland 8-0
11’ O’Gara conversion: Ireland 10-0
13’ O’Brien try: Ireland 15-0
13’ O’Gara conversion: Ireland 17-0
38’ Boss try: Ireland 22-0
38’ O’Gara conversion: Ireland 24-0
40’ Earls try: Ireland 29-0
40’ O’Gara conversion: Ireland 31-0
40’ Trimble try: Ireland 36-0
49’ Earls try: Ireland 41-0
49’ O’Gara conversion: Ireland 43-0
50’ Artemiev try: 43-5 Russia
51’ Rachkov conversion: 43-7 Russia
59’ Simplikevich try: 43-12 Russia
65’ Kearney try: Ireland 48-12
66’ O’Gara conversion: Ireland 50-12
74’ Jennings try: Ireland 55-12
75’ Sexton conversion: Ireland 57-12
80’ Buckey try: Ireland 62-12