Boris Johnson repeated the cries heard in offices across the country on Friday afternoon, as he struggled to comprehend what was happening during women's double sculls rowing final.
"What is this?" he asked the soldiers he was watching the race with. "This is it, we're watching, this is it, come on whoever you are doing whatever you're doing, fantastic!"
As Britain's Katherine Grainger and Anna Watkins approached the line he yelled: "She's going to win!" Before being told that the pair were only half way through the race.
"Oh, half way, sorry," the mayor apologised. "Pick it up now, they're a length ahead now, come on Team GB!"
Boris, who has been omnipresent during the Games, said that the Olympics so far had been a "Himalayan range of high points".
"For me every hour that goes by without a snafu is a success," he said.