LONDON: Usain Bolt and his fellow Jamaicans may have the world record as well as gold in their sights when they run the 100 meters relay on Saturday, the busiest day for medals at London 2012 when 32 golds, from sailing to taekwondo, will be decided.
On the last day of competition in the main Olympic stadium, packed every day with capacity 80,000 crowds, Mo Farah's bid to add the 5,000 title to the 10,000 crown he won last weekend could give the host nation the perfect end to the meet.
Organizers will then 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."
He added that the sport was not yet over and among the highlights on a packed Saturday will be the men's soccer final between Mexico and Brazil which the five-times World Cup winners have never won.
Saturday's London Olympics program also sees five men's boxing finals, the women's basketball, volleyball and handball finals, and a men's hockey final between rivals Germany and the Netherlands that could be a classic.
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 United States. 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.
Farah is world champion in the 5,000 but looked tired in the heats and may find that challengers such as Ethiopians Dejen Gebremeskel and Hagos Gebrhiwet, Kenya's Isiah Kiplangat Koech and American Bernard Lagat have fresher legs.
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.
That took the hosts to 26 gold medals, comfortably beating their Beijing tally of 19 and the highest in over a century. It puts them third in the overall medals table, which the United States top with 41 to China's 37.
The shadow of cheating loomed large over the athletics late on Friday when 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.
Also appearing in the men's 4x100 relay semi-finals were American Justin Gatlin and Briton Dwain Chambers, both time-served drugs cheats.
France and Kenya confirmed pre-Games positive tests on distance runners Hassan Hirt and Mathew Kisorio, Kenya strongly denying Kisorio's allegations that blood-doping and steroid use were widespread in Kenya.
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.
Coe reminded reporters that the Games had not yet finished but said he was looking forward to the closing show titled "A Symphony of British Music".
"Party, party, party," he told a news briefing when asked to describe the final act in a drama-filled few weeks.
As well as a "hit list" of more than 30 popular songs from the last 50 years, it 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."
At Wembley on Saturday, a Brazil soccer side boasting Neymar, Oscar and the tournament's top scorer Leandro Damiao are under pressure to live up to their status as favorites and improve on their silver medals of 1984 and 1988.
The women's basketball final sees France try to derail the all-conquering U.S. team.