New Zealand moved smoothly from winning the World Cup on home soil to dominate 2012 despite a blip in their final match against England that will give the rest of the rugby world a glimmer of hope.
Led magnificently by indefatigable captain Richie McCaw, who is now to take a sabbatical to recharge his batteries, the All Blacks won the newly-launched Rugby Championship that included Australia, South African and newcomers Argentina.
The side went undefeated, with their final match against Australia an 18-18 draw. The performances of fly-half Dan Carter ensured he was named the International Rugby Board player of the year for a second time (after 2005).
The Championship's inclusion of Argentina was a particular success, and the Pumas' exposure to that level of rugby can only bode well for the sport in South America as a whole.
The All Blacks moved on from their three-Test summer series victory over Ireland and their successful Championship to claim three straightforward wins over Scotland, Italy and Wales in their autumn Tests.
But they finally came acropper in their final match of the calendar year, England ending the world champions' 20-Test winning sequence with a famous 38-21 victory at Twickenham -- it was also the Kiwis' first loss on their end-of-year northern tour in a decade.
"All the boys will take a wee while to get over it but they will come back next year and this (defeat) will remind them what it's all about," said skipper McCaw.
"If there's a positive out of it, that's probably not a bad thing to have next year."
Another team to deliver on their World Cup promise, at least until March, were Wales, who produced a third Six Nations Grand Slam in eight years.
The Welsh team saw off France 16-9 in their final match of a generally poor championship to add to victories over Ireland (23-21), Scotland (27-13), England (19-12) and Italy (24-3).
But that success did not last long after a losing three-Test series in Australia in the summer followed by losses in the autumn to Argentina, Samoa, New Zealand and again the Wallabies.
The string of seven successive defeats meant Wales fell out of the top eight in the IRB rankings and were drawn alongside England and Australia for the 2015 Rugby World Cup in England.
This means one of the sport's traditional powers will be knocked out before the quarter-finals, with only the top two teams from each of the four pools going through to the knockout stages.
In the southern hemisphere's elite franchise competition, the Waikato Chiefs downed South Africa's Coastal Sharks 37-6 to win the Super 15, the schedule of which has been altered for the 2013 season to accommodate the nine-game schedule of the British and Irish Lions Tour to Australia in June.
Australian teams will take a break from Super Rugby when the Wallabies play the Lions in three Tests on June 22, June 29 and July 6.
Similarly, there will be staggered rest periods for teams from South Africa and New Zealand.
European club competition saw Irish province Leinster claim a second successive European Cup title.
Leinster, with full-back Rob Kearney named as European player of the year, outscored Irish rivals Ulster 42-14 in a five tries to one thrashing.
Veteran France scrum-half Dimitri Yachvili kicked all of his side's points as Biarritz beat French rivals Toulon 21-18 to win the second tier European Challenge Cup.
In South Africa, fly-half Demetri Catrakilis kicked nine unanswered final-quarter points to guide Western Province to a shock 25-18 victory over the Sharks to win the Currie Cup final.
Domestically, league table toppers Harlequins won the English Premiership with a 30-23 victory over Leicester for a first ever title.
Welsh rugby great Shane Williams scored a try two minutes from time to end his stellar competitive club career with a 31-30 win over Leinster to claim the Celtic League title.
Toulouse were crowned French champions for the 19th time after battling to a hard-fought, tryless 18-12 victory over Toulon in the Top 14 final at the Stade de France, ex-All Black Luke McAlister getting all the winning points.
The IRB's World Sevens Series was claimed by New Zealand for the 10th time in 13 seasons, the season's top scorer and All Black playmaker Tomasi Cama taking the player-of-the-year award.