The likes of Sachin Tendulkar and the Indian cricket team, Filipino boxer Manny Pacquiao and Chinese tennis player Li Na had years ranging from the mediocre to the downright disastrous.
There was better news in geopolitical terms when India decided to resume cricketing ties with neighbours Pakistan, while the sporting sphere avoided any serious repercussions from China's bitter territorial dispute with Japan.
Brilliant performances from swimmers Sun Yang and Ye Shiwen led the way as China won 38 golds in London to finish second on the medals table, but there was controversy as well as glory for the Chinese.
China was furious at suspicions of doping levelled at Ye, shamed by the scandal involving their badminton team and stunned by the second successive Olympic failure of hurdler Liu Xiang.
South Korea's heavy investment in Olympic success also paid healthy dividends with 13 golds and a best ever finish of fifth on the medals table, pushing them ahead of traditional middle-ranking powers Germany, France, Australia and Japan.
While the Chinese remained Olympic pacesetters, in football they continued their long pattern of underachievement despite the presence of Didier Drogba and Nicolas Anelka in their domestic league.
Instead, it was their Japanese and Korean neighbours who again shared Asian bragging rights in the world's most popular sport.
Japan were in a class of their own on the international stage with a number of eye-catching performances as they moved to the brink of being the first team to qualify for the 2014 World Cup in Brazil.
Alberto Zaccheroni's side made a major breakthrough by beating France 1-0 in a friendly in Paris and Shinji Kagawa moved to Manchester United in June.
Ulsan Hyundai became the third K-League club in four years to win the Asian Champions League, going unbeaten through the continent's top club competition and clinching the title with a 3-0 win over Al Ahli of Saudi Arabia.
While Ulsan's triumph was a welcome turnaround after the Korean match-fixing scandal of 2011, controversy continued to dog Asian football.
The governing Asian Football Confederation spent the year trying to rid themselves of suspended president Mohamed Bin Hammam, long after the Qatari was first banned by FIFA for alleged bribery in May 2011.
Indonesian clubs remained stuck in the middle of a dispute over governance of the sport in the nation and Paraguayan striker Diego Mendieta was left to die in a hospital waiting on four months' wages owed by his former club.
Pacquiao, arguably the greatest ever pound-for-pound boxer, stood at a crossroads at the end of 2012 after a stunning knockout at the hands of Mexican Juan Manuel Marquez in December handed him a second defeat of the year.
The 34-year-old Filipino, who has won world titles in an unprecedented eight weight divisions, may fight again but it was a signal that his illustrious career may be drawing to a close.
India have rarely thrived at the Olympics and a reminder of their low expectations came when their unprecedented six-medal haul in London was hailed as a triumph.
The Indian Olympic Association undermined even that moderate success when, despite several warnings, it was kicked out of the Olympic family after allowing government interference in its elections.
The country's cricketers can usually be relied upon to raise sporting spirits in the world's second most populous nation but the much vaunted India team lurched from one defeat to another.
The retirement of batting greats Rahul Dravid and V.V.S. Laxman deepened the gloom and even Tendulkar, who became the first cricketer to hit 100 international centuries this year, laboured in the twilight of his career.
Sri Lanka won good reviews for its hosting of the Twenty20 World Cup but the hosts could not manage to provide Asia with a champion and succumbed to West Indies in the final.
Li won a WTA title at Cincinnati and reached three other finals to cement her position as a top 10 player but she never got past the fourth round at a grand slam in her attempts to back up her breakthrough 2011 French Open triumph.
Kei Nishikori finally gave Asian fans a men's tennis player to cheer when he crashed into the world top 20 and became the first local to win the Japan Open for his second ATP title.
Japanese pitcher Yu Darvish made a good start to his Major League baseball career with the Texas Rangers, being credited 16 wins in 29 starts and winning the club's Rookie of the Year award.
Millions of dollars continued to be pumped into golf in Asia but despite the many lucrative tournaments being played at sumptuous courses around the region, local success at the top level was rare.
India's Jeev Milkha Singh and Thai Thongchai Jaidee claimed titles on the European Tour but Hiroyuki Fujita's four wins on the Japan Tour were enough to make him Asia's top ranked golfer at world number 49.
There were signs that China might be on the verge of producing some promising talent when 14-year-old Guan Tianlang ensured he would become the youngest player to compete at the US Masters by winning the Asia-Pacific Amateur Championship.
Taiwan's Yani Tseng led the continued Asian dominance of women's golf by retaining the number one ranking throughout the year, while eight of the top 10 in the world are from the continent.
Perhaps the biggest development for the future of sport in Asia, and in particular for the continent's half a billion Muslim women, came when FIFA lifted its ban on the wearing of head scarves in competition and women athletes from Saudi Arabia and Qatar competed for the first time at the Olympics.
Teenager Wojdan Ali Seraj Abdulrahim Shaherkani became Saudi Arabia's first female Olympian with a brief appearance in the London judo competition.
"I advise all Saudi women to take part in sports," she said.
- Sports & Recreation
- Sachin Tendulkar