INVESTORS joined in the final lap of the Olympic Games saga, pushing the Hang Seng Index up 102.10 points to 7,581 on heavy buying. Turnover climbed to $3.43 billion as the Olympic Games fever gripped the market. HG Asia sales director David Bulbeck said: ''There was a bit of euphoria ahead of the International Olympic Committee (IOC) decision on the venue of the games. ''The feeling is that Beijing was likely to be awarded the right to host the Games. There was no other news to drive the market right now.'' Ladbroke's of London reported yesterday that Beijing was the hot favourite to get the Games. It put the latest odds for Beijing at 11 to 4 while Manchester had gained second place, at 4 to 1. Vickers Ballas director Barry Yates said if China was awarded the Games, the market would applaud the decision. 'It would be a vote of sentiment and the market could easily surpass the 7,600-mark and set a new record,'' he said. He added that the rally would be a temporary one because the political problems in the territory remained. China-related stocks and H shares rode high on the market sentiment. The economy of the mainland was expected to be given a big boost if Beijing won the fierce competition. Schroder Securities assistant director Peter So said the Chinese Government had indicated it would open up its economy, improve its infrastructure and speed up economic reforms. Tsingtao Brewery rose 30 cents to $6.10 while Shanghai Petrochemical increased four cents to $1.96. CITIC Pacific rose 40 cents to $17.50. New World Development, which has the largest undeveloped land bank in China, rose 40 cents to $20. As the Games fever raged on, brokers also cautioned that the bubble might burst if China missed out in its bid. Mr Yates said: ''If China fails to get the vote, there will be a lot of long faces,'' The positive sentiment was expected to turn quickly if the result went against Beijing. But Mr So expected the market to fall regardless of whether China was awarded the Games or not. ''If China is awarded the Games, I expect profit-taking on selective counters and if it is not awarded the Games, the market will come under selling pressure,'' he said. Details on Page 16