By Mitch Phillips

RIO DE JANEIRO (Reuters) - Mo Farah survived another stumble to battle through to the final of the 5,000 meters on Wednesday as the Briton remained on course for a prized Olympic distance 'double-double'.

Farah recovered from a fall to win the 10,000 gold last weekend and almost went down again on the last lap of his heat in the shorter race after being clipped by American Hassan Mead, who did fall and missed out on qualification.

An initial appeal by the Americans was rejected but a second plea, offering new video evidence, was accepted and Mead was installed in the field for Saturday's final.

Farah is seeking to become the second man after Finland's Lasse Viren in 1976 to retain both the 5,000m and 10,000m titles but said he still felt the strain of the longer race in his legs during Wednesday's run in 32 degrees Celsius heat.

"It's hot, I've just got to recover... I haven't recovered (from the 10,000m) as well as I'd wanted," Farah said.

"I got clipped, I just had to stay on my feet. But now I just have to recover, chill in my room."

Farah just about retained his balance after his stumble to qualify safely in a heat won by Ethiopian Hagos Gebrhiwet, who is likely to be one of his chief rivals in the final.

Gebrhiwet, 22, missed the 10,000m to concentrate his efforts on the shorter race after taking silver and bronze behind Farah over 5,000 in the last two world championships.

Dejen Gebremeskel, who took silver to Farah's gold in the London Olympics and also skipped the 10,000 in Rio, is also likely to challenge in the final, and qualified safely from the second heat.

Paul Chelimo, who switched allegiance from Kenya after joining the U.S. army, was the fastest qualifier, running a personal best 13 minutes 19.54 seconds, while another Kenyan-turned-American Bernard Lagat, appearing in his fifth Olympics, also advanced.

The 41-year-old Lagat won a bronze for Kenya in the 1500m at Sydney in 2000 and a silver in the same event in Athens four years later before he became an American citizen in 2005.

(Editing by John O'Brien)