The decision went unanimously in favour of the 39-year-old Klitschko after he dominated the fight against Briggs to defend his title for the fifth time.
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.”
Klitschko’s brother Vladimir holds the WBO, IBO and IBF world heavyweight titles and looks set to fight Britons David Chisora on December 11, in Germany.
Another Briton, David Haye, is the only holder of an officially sanctioned belt in the heavyweight division outside of the Klitschko brothers. Haye is the reigning WBA champion.
Meanwhile, undefeated Lucian Bute retained his IBF super middleweight title with a ninth-round technical knockout of mandatory challenger Jesse Brinkley in Montreal.
Romanian/French-Canadian southpaw Bute sent his American opponent crashing to the canvas for a third time with a big left uppercut at 2:48 in the ninth. Bute had used the same weapon to floor Brinkley in the fifth and eighth rounds.
The champion improves to 27-0 (22) while Brinkley is now 35-5. Bute has now defended his belt six times since 2007.