The challenger looked in danger of going down on several occasions and was saved by the bell at the end of the seventh round when Klitschko had him on the ropes.
It was only the fifth time Klitschko had failed to knock out an opponent -- he has now won 41 of 43 fights in his career, 38 of them by knockout.
"He's the best man I've ever boxed against," said Briggs, 38, who at 119 kilos was five kilos heavier than the Ukrainian.
"He has so much power, he's a very great fighter."
(Writing by Brian Homewood in Berne; Editing by Ken Ferris)