The undisputed heavyweight champion, who returns to London for the first time since his victory over Evander Holyfield this morning, was at ringside with his manager, Frank Maloney, to run the rule over Grant, who is being spoken of as an opponent for Lewis next year.
Not only was the 6ft 7in Grant knocked down twice in the opening round, but at the time of the stoppage, midway through the 10th, he was behind on all three judges' cards.
"I knew when I got knocked down in the first it would be a test of my faith," said the unbeaten Grant, who improved his record to 32-0 with his 22nd stoppage. "I wasn't going to quit, it's not even in me."
Asked about the prospect of fighting Lewis, Grant said: "That is the fight I want. I've wanted that fight since six fights ago."