Whitlock, who had not competed since last year's Olympic Games in Rio de Janeiro, became the first athlete from Britain to retain a world title as he again reigned supreme on the pommel horse.

The Olympic champion scored a total of 15.441 after a near faultless routine, comfortably beating nearest challenger David Belyavskiy of Russia at the Montreal Olympic Stadium.

The Russian gymnast shrugged off the disappointment of his fall in the all-around earlier in the week, which cost him the gold medal, to take silver on 15.100.

Xiao Ruoteng of China did enough for the bronze medal with a score of 15.066.

"I was pretty nervous as I had to wait a long time but I'm so, so happy now," said Whitlock. 

"I can't be more pleased really. 

"Just before competing I spoke to my coach and we decided to up the routine by .1 compared to qualifying. 

"Today I'm so happy, my build up hasn't been perfect but I'm here with the title again, I can't believe it. 

"It feels very, very special, I've worked so hard and to defend my title is a big moment for me, that's what I've always aspired to do."

Shirai is renowned for his twisting floor routine and he again dazzled the crowd on his way to his third consecutive crown on the apparatus.

The Japanese star blew the rest of the field out of the water with a routine which yielded a superb 15.633 points, a huge 1.100 margin in front of silver medallist Artem Dolgopyat of Israel.

Yul Moldauer of the United States took bronze.

Eleftherios Petrounias of Greece justified his nickname of "Lord of the Rings" as he won his third straight major rings event to add to his 2015 world title and 2016 Olympic gold medal.

Petrounias was pushed all the way by Russia's Denis Abliazin but managed to emerge victorious with a score of 15.433.

Abliazin was forced to settle for the silver medal on 15.333, while bronze went to China's Liu Yang on 15.266.

China's Fan Yilin was involved in an unprecedented four-way tie for gold on the uneven bars at the 2015 World Championships in Glasgow but was the clear winner on the apparatus this time, topping the podium on 15.166 points.

Fan narrowly beat Russian Elena Eremina, who took silver on 15.100, and Belgium's Nina Derwael who earned bronze with 15.033.

There was gold medal success for Russia on the opening day of apparatus final as Maria Paseka defended her vault crown on 14.850.

Jade Carey of the US was the recipient of the silver medal after her routine yielded 14.766, while Giulia Steingruber of Switzerland, the bronze medallist at Rio 2016, was third with a total of 14.466.

The Championships in Montreal conclude tomorrow.