American Michael Phelps bids goodbye to Olympic competition as the focus switches from swimming to track and field Friday at the 2012 London Olympics
Phelps will seek his third gold medal of the London Games when he swims in the 100-meter butterfly race. The field of competitors includes South African Chad le Clos, who upset Phelps in the 200-meter butterfly final.
A win Friday would also give Phelps his third consecutive gold medal in the event after victories in 2004 and 2008. He pulled off the feat Thursday in the 200-meter individual race, becoming the first swimmer in Olympic history to win the same event at three consecutive Games. Phelps is the most decorated Olympian in history with 20 total medals.
On the women's side, Britain's Rebecca Addington will try and boost the host nation's gold medal haul when she defends her title in the 800-meter freestyle, while teenaged American swimmer Missy Franklin will go for her third gold in the 200 meter backstroke, going against two-time winner Kirsty Coventry of Zimbabwe.
The track and field competition gets underway at Olympic Stadium with the women's 10,000-meters final, as world champion Vivian Cheruiyot of Kenya takes on defending Olympic champion Tirunesh Dibaba of Ethiopia. Meanwhile, Ukraine's Nataliya Dobrynska will begin defense of her 2008 championship in the heptathlon, against a lineup featuring world champion Tatyana Chernova of Russia and British hopeful Jessica Ennis.
The United States is leading China in the overall medal count, 37 to 34, and are tied in the gold medal category with 18. South Korea is a distant third in the overall medal count with 14.
Photo Gallery: Day 6 of Competition