As the tennis singles season comes to end this weekend, great games are going hand-in-hand with the scandals. The top eight men in 2007 contest the Masters Cup in Shanghai, China with semi-finals and the final live on Diema-2 over the weekend. At the same time, more news is emerging about the dark side of tennis - Italian Alessio Di Mauro suspended for nine months and fined $60 000 for betting on events and Czech Jan Hernych is the latest player approached and asked to lose matches for money.

Roger Federer was honoured in Shanghai after finishing the year as the world's top player for the fourth season in a row. The Swiss then suffered a shock defeat by Chile's Fernando Gonzalez in his opening round-robin match at the year-ending event but then he beat Russia's Nikolay Davydenko to keep his chances of defending the title alive.

Federer was scheduled to play Andy Roddick on November 16. The American is having a perfect Masters so far (2-0). The competition should also make fine preparation for the Davis Cup final between the United States and Russia at the end of the month (November 30 - December 2, Portland, Oregon). "The Davis Cup is my top priority for this year," Roddick said.

Before the last games in the other group, David Ferrer of Spain had achieved two victories, his compatriot Rafael Nadal and Frenchman Richard Gasquet each won and lost a match and number three in the world Novak Djokovic had lost both of his matches so far.

The Tennis Masters Cup is the third evolution of a championship which began in 1970. It was originally known simply as The Masters tournament, and was a year-end showpiece event between the best players on the men's tour, but did not count for any world ranking points. For many years, the doubles event was held as a separate tournament the week after the singles competition. But more recently they have been held together in the same week and venue. In 2009 the Masters Cup will be renamed the ATP World Tour Finals and it will be staged at The O2 in London from 2009 to 2013.

In more concerning news, an ATP investigation launched in April found that the 31-year-old Di Mauro had bet on tennis matches during the period between November 2006 and June 2007. He is the first player to be sanctioned under the Anti-Corruption Program, however there is no evidence of any attempt by the player to bet on his own matches or to affect the outcome of any matches. Di Mauro, who is currently 124th in the world rankings, will begin his suspension on Monday and will be eligible to return in August 2008.

Czech Jan Hernych said he was approached in Russia last year and asked to lose first-round matches at ATP tournaments in Moscow and St. Petersburg. "Someone called me from the hotel's reception to my room, asking whether I wanted to sell a match, if I wanted to lose. I rejected. I think that anyone who would accept it is absolutely mad." Hernych, currently ranked 165th, said he was not offered a specific sum of money. "They wanted to know whether I was willing to negotiate with them," he added.

Talk of match-fixing has swirled around tennis for months. An online gambling company voided all bets when fourth-ranked Nikolay Davydenko withdrew against 87th-ranked Martin Vassallo Arguello in the third set of a match in Poland in August, citing a foot injury. Unusually large amounts were wagered on the lowly ranked Argentine throughout the match, even after he lost the first set 6-1. The ATP is investigating. Since then, several players have said they have been approached about influencing a match. Belgian player Gilles Elseneer said he was offered, and turned down, more than $100 000 to lose a first-round match against Potito Starace of Italy at Wimbledon in 2005.