* Mo Farah wins 5,000m to add to 10,000m title
* Syrian athlete expelled from Games for doping
* Mexico stun Brazil to win men’s soccer final 2-1
* Usain Bolt returns to the track in sprint relay
* Busiest day of Games with 32 golds decided
By Mike Collett-White and Matt Falloon
LONDON, Aug 11 (Reuters) - Britain’s world champion Mo Farah stormed to the Olympic 5,000 metres crown on Saturday, just days after winning gold in the 10,000m and kicking off the last night of track and field drama in style.
The athletics competition in the Olympic stadium reaches a crescendo with the men’s 4x100 metres relay featuring the world’s fastest man - Usain Bolt - and his fellow Jamaican sprinters, who will hope to post a world record.
Russia’s world champion Mariya Savinova saw off a late challenge from South African Caster Semenya to win the women’s 800m title and the United States won the women’s 4x400m relay.
Farah, a big favourite for the hosts who are enjoying their biggest medal haul at a Games for more than a century, dropped to the track to cheekily squeeze in some sit ups after sprinting away to claim Britain’s first Olympic men’s 5,000m title.
He is the seventh man to win the 5,000m and 10,000m double at the same Olympics.
The final few moments of Olympic glory in track and field bring a close to an eventful penultimate day of the Games in which sporting prowess did not always dominate the headlines.
A Syrian athlete was expelled after testing positive for a banned substance and a South Korean soccer player was barred from a medal ceremony for a political gesture - both cast a shadow over the day with the most golds up for grabs.
Ghfran Almouhamad, who competed in the women’s 400 metres hurdles, was the 11th athlete to be thrown out of the Games since the start of the Olympic period which began on July 16.
The 10-strong Syrian team has attracted considerable media attention during London 2012, less for its sporting achievements than the bloody conflict raging at home between rebels and forces loyal to President Bashar al-Assad.
Politics also crashed the party when the International Olympic Committee (IOC) called for a South Korea soccer player to be banned from a medal ceremony after he held up a poster referring to his country’s long-running territorial dispute with Japan.
Five-time world champions Brazil’s long quest for Olympic soccer gold continues after Mexico stunned the stylish South Americans with a 2-1 win.
Oribe Peralta put Mexico ahead after just 28 seconds and added their second in the 75th minute with a header before Hulk replied for Brazil in stoppage time in front of a London Games record of 86,162 fans at Wembley Stadium.
Brazil’s women provided some consolation, beating the United States to gold in the volleyball.
Organisers have less than 24 hours to prepare the arena for the closing ceremony on Sunday, which artistic director Kim Gavin said would be a celebration of British pop music from the last 50 years.
The Spice Girls, One Direction, George Michael and The Who are expected to perform as London prepares to bid goodbye to what the Guardian newspaper dubbed the “feelgood Games”.
Games chief Sebastian Coe declined to compare London with other Olympics, but said simply: “I’m pretty pleased with the way we’ve delivered.”
“Party, party, party,” he told a news briefing when asked to describe the closing concert ending a drama-filled few weeks.
Forecasters point to a warm and dry day in London to bring to a close a festival of sport that has helped to lift the gloom in recession-hit Britain.
As well as a “hit list” of more than 30 popular songs, the closing ceremony will feature thousands of athletes and performing volunteers as well as a section devoted to the next summer Olympic hosts, Rio de Janeiro.
“I think it’s a gift that we’ve got Rio next because their eight minutes is so wonderful and really full of that samba beat,” Gavin said of the 2016 hosts. “It’s really creative and very cultural and feels really great.”
The sport was far from over, however, with 32 gold medals, the most of any day, being decided on Saturday.
The sprint relay gives 100 and 200 champion Bolt the chance to better Jamaica’s world record of 37.04 seconds set in last year’s world championships and win his sixth sprint gold in two Olympics.
If Jamaica’s relay squad wants inspiration, it need look no further than the U.S. women’s 4x100 quartet who left their Jamaican rivals trailing on Friday and took more than half a second off a record set by East Germany in 1985.
The U.S. men look certain to push Jamaica all the way on Saturday after running 37.38 seconds in their semi-final, the third fastest time ever, while resting two of their best racers.
Jamaica, resting Bolt, were only 0.01 seconds slower.
Dubbed “Usain Bolt on water”, Britain’s Ed McKeever won the men’s K1 200 canoeing gold, the first to be awarded in the new shorter and more explosive Olympic distance.
The hosts have claimed 27 gold medals, comfortably beating their Beijing tally of 19. It puts them third in the overall medals table, which the United States top with 42 to China’s 38.
Syrian Almouhamad’s ejection follows a Friday where two former dopers won gold.
Asli Cakir Alptekin, who served a two-year ban for doping from 2004, led a Turkish 1-2 in the women’s 1,500, a distance riddled with drugs in recent years.
Russia’s Tatyana Lysenko, who watched the 2008 Olympics on TV while serving a two-year doping ban, won the women’s hammer.
Saturday’s men’s 50km walk was missing defending champion Alex Schwazer of Italy, excluded from the Games for using the blood-boosting erythropoietin (EPO).
The race was won by Russia’s Sergey Kirdyapkin, who set an Olympic record of three hours 35 minutes and 59 seconds.