By Gennady Fyodorov
With just seconds remaining before the final gong, Lebedev caught Jones with a flurry of punches to send the American to the canvas.
"I was prepared for a long fight," Lebedev, who was trained for this fight by former undisputed welterweight champion Kostya Tszyu, told reporters.
"I knew it would be a tough fight because Roy is a legend. People, who had said it would be easy, just don't know anything about boxing."
Jones would not say if he was ready to retire after losing for the seventh time in his last 12 fights.
"It was a great fight. I love Moscow and hope to come back here again," he said. "Denis is a good fighter but I think overall, it was a close fight. I just lost concentration near the end and didn't see his punch coming."
The American began the fight at Moscow's Krylatskoye arena in his usual showboating style, dropping his hands and challenging Lebedev to hit him.
The Russian southpaw first connected with a straight left near the end of round four, then dominated the majority of the later rounds, forcing his opponent against the ropes.
Jones briefly countered with a right-left combination in the ninth but ran out of gas in the final round.
Lebedev, known for his devastating left hook, waited for his opponent to tire before unleashing a flurry of punches that knocked out Jones with about 12 seconds remaining.
(Editing by John Mehaffey and Mark Meadows)
