With two nights of competition left in Olympic Stadium, the relays finally get started. The women’s 4x400m and men’s 4x100m will be events not to be missed tonight, along with the women’s 1500m.

In a little over a month, Ashton Eaton has broken the world record in the decathlon and now become the 12 American Olympic champion in the event, yet so naive about his greatness.

Ashton Eaton became the twelfth American man to win decathlon gold Thursday night, joining an impressive list of boyhood heroes who defied physics and their own bodies to wear the title of "world's greatest athlete."

With his third career world record earning him his first 800m gold medal, an argument can now be made that Kenya's David Rudisha, not Jamaica's Usain Bolt, is the most dominant athlete in track and field.

And the hits just keep on coming. An already depleted American 4x400 team took another hit Thursday afternoon when Manteo Mitchell allegedly broke his leg with 200m left during his turn around the track.

With the U.S. down its two biggest stars, LaShawn Merrit and Jeremy Wariner, the future is now for a group of first time Olympians who have been entrusted with extending American dominance in the 4x400m.