Sprint showdown

Usain Bolt and Justin Gatlin will face off in another final on Thursday after both won their men’s 200m semis.

Bolt clocked 19.95 seconds — over half a second outside the world record he set in the same stadium in winning gold at the 2008 Beijing Olympics.

“I’m trying to preserve as much as possible for the final. The 200m is my best event,” said the Jamaican superstar, who edged Gatlin in Sunday’s 100m to retain his title.

The American, the 2005 champion, was also impressive in running 19.87s.

Got the drop on CNN . . .