The agency's series of commercials, including the popular "'Ave it" film featuring the hapless Kay's footballing skills, took both platinum and gold at the awards ceremony in London this week.
John Smith's won the top honour in a close race against Saatchi & Saatchi's commercial for the NSPCC, which delivers the charity's message by featuring cartoon children suffering at the hands of violent parents.
Mike McKenna, the chairman of the judging panel, said the two campaigns were the only realistic contenders for the platinum award, which John Smith's had narrowly shaded. "'Ave it' echoes around every playground and every council pitch in the land," he added.
TBWA's haul included four golds for John Smith's. Among them was the Ken Grimshaw memorial honour for the best use of humour, which was awarded for the commercial in which Kay tries to put his still-youthful mother into an old-people's home.
The agency's deputy creative director, Paul Silburn, who wrote the John Smith's campaign, picked up the President's Award.
The agency also struck gold for its "morphing" commercial publicising Channel Five's Michael Jackson documentary, which took the top honour for the best use of a production budget under £40,000.
Other golds went to Fallon's United Airlines film for best use of dialogue, while D'Arcy and Faulds were similarly honoured for their press work on Auto Trader and social workers recruitment respectively.
BMP DDB received a gold for its Harvey Nichols print work, which was judged the best consumer campaign or series. A gold for the best cinematography went to Campbell Doyle Dye for its "lucky star" commercial promoting the Mercedes Benz SL500.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the Forum here.