Stadium will see the last 15 medals go up for grabs, with the men's marathon getting things under way at 11:00am local time (1000 GMT).
The Olympic rings are illuminated during the Opening Ceremony at the 2012 Summer Olympics in London. (AP Photo/Matt Slocum)
Kenya's two-time world champion Abel Kirui is hoping to add an Olympic marathon gold to his wins at the 2009 and 2011 world championships as he bids to emulate late compatriot Samuel Wanjiru, winner in Beijing four years ago.
The Kenyans can also count on the 2012 London marathon winner Wilson Kipsang, hugely impressive when winning in the British capital in April.
Ethiopia's threat comes from Ayele Abshero and Dino Sefer, setting the stage for a battle played out against the backdrop of London's most iconic landmarks before finishing on The Mall in the shadow of Buckingham Palace.
The United States, who are likely to finish the 2012 Olympics on top of the medal table after losing out to China four years ago, should add to their haul on Sunday with gold in the men's basketball final.
The Americans' Dream Team of NBA stars will be chasing a 14th gold medal and their fifth in sixth Olympiads when they face Spain.
The Americans have run through the tournament undefeated, just as they did in 2008 when they beat Spain 118-107 in the Beijing final.
Five members of that team and five from the US 2010 world championship team are in the London lineup.
The US team is 61-1 since settling for bronze in 2004 and revamping the program to create the 2008 "Redeem Team" and the current US squad of NBA multi-millionaires whose dynasty inspires top efforts from every rival.
Meanwhile the final medals in boxing will be decided along with golds in women's modern pentathlon, men's water polo, volleyball and freestyle wrestling.
Attention will then turn to Sunday's closing ceremony, which is being billed as a diverse "Symphony of British Music."
The Spice Girls, George Michael, Muse and Ed Sheeran are among the acts expected to play at the ceremony which will feature more than 4,000 performers, including 380 schoolchildren.
"We want it to be the best after-show party there has ever been," artistic director Kim Gavin said. "Any more than that and we would spoil the surprise."
The ceremony will see London hand over to the Rio 2016 Games, and the Olympic flame -- which has been alight at the east London stadium for two weeks -- will be extinguished.
The ceremony's pre-show entertainment begins at 1900 GMT, with the main ceremony, from 2000 GMT, scheduled to last up to three hours.