SINGAPORE (AFP) - Singapores ruling Peoples Action Party (PAP) was returned to power on Sunday with a huge majority but lost a key district to the opposition, costing a senior cabinet minister his job. Prime Minister Lee Hsien Loong thanked voters for their support as unofficial reports had the PAP winning 81 of the 87 seats, compared with its victory in 82 out of 84 seats in Singapores last general election in 2006. Foreign Minister George Yeo lost a hotly contested group constituency whose five seats went to the Workers Party, forcing him out of the cabinet. A single-seat ward also went to the Workers Party. The win in six seats may be modest by international standards but it is the best ever performance by the opposition since Singapore became independent from the Malaysian federation in 1965. The oppositions previous best result was four seats in 1991. Its the first time in 20 years that they have won this big, said Bridget Welsh, a political science professor at the Singapore Management University. She stressed the significance of the oppositions first ever win in a group representation constituency (GRC), a setup widely seen as favouring the ruling party but now shown to be vulnerable. The GRCs have been a cornerstone of one-party dominance in the Singapore state, and the breaking of its GRCs is really allowing a diversity of political views in the country, Welsh said. Six opposition parties took part in the election, with the modest goal of winning more seats from the PAP resigned to the dominance of the party that led Singapore to political independence and economic prosperity. Welsh said the outcome would trigger an intense period of reflection for the PAP, which admitted during the campaign that voters were disenchanted with its policies on housing and immigration as well as the rising cost of living. Four days before the election, the prime minister issued an unprecedented apology to voters for government shortcomings since the 2006 election and vowed to do better if given a new mandate. Compulsory voting and a clear tropical sky ensured a high turnout during 12 hours of polling on Saturday. Election officials said 83 percent of the 2.21 million voters had cast ballots by 5:00 pm (0900 GMT), three hours before polling stations closed. It was the most keenly fought election in Singapore, with six small parties dividing electoral districts among themselves to avoid three-way fights with the PAP and scatter the superior resources of the government. The opposition has come together in terms of not contesting against each other. When push came to shove, they put aside personal differences for the larger cause of opening up political space, Welsh said. The PAP was co-founded by the prime ministers father Lee Kuan Yew, who governed Singapore for 31 years and was reelected to parliament on Saturday without any opposition at the age of 87. Tens of thousands of vocal supporters attended opposition rallies held over the past week, far greater than the PAPs crowds. The opposition also relied heavily on the Internet, particularly social media platforms such as Facebook, YouTube and Twitter, because the mainstream local media are widely regarded as PAP mouthpieces. The PAP has long relied on its economic record to convince Singaporeans to return it to power and kept the opposition in check by imposing curbs on political activity except during elections. The economy grew a record 14.5 percent in 2010 and per capita gross domestic product stood at Sg$59,813 ($48,271), according to the statistics department, making Singaporeans the second wealthiest Asians after the Japanese. But the prosperity has not been spread evenly, and inflation this year is forecast at 3.0-4.0 percent, high by Singapore standards. Apart from seats won or lost, the PAPs overall share of the popular vote in Saturdays polls was being closely awaited. The party won 67 percent of the overall vote in 2006, down from 75 percent in 2001.