While it was a day to honor Prince William, who was celebrating his first Father's Day, his growing son stole the show today, making his first public appearance since the tour last month to Australia and New Zealand, just a month shy of his first birthday.

Kate and Baby George came to cheer on Prince William as he and Prince Harry duked it out on opposite sides of the Jerudong Trophy match at the Cirencester Park Polo Club, raising money for their charities.

George, adorable in a pair of red and white striped overalls and a mini white polo shirt, proved even at an early age he's a sportsman in the making like his dad.

He was intrigued with a polo mallet. George kept the crowd absorbed, kicking a quilted soccer ball as he was wriggling around the field where his father was on his horse. With the aid of his mother, Prince George proved he's nearly walking on his own.

Kate looking casual in a striped Breton top and skinny jeans.

The pint sized blond, who is third in line to the throne, looked like a mirror-image of his dad at the same age, even pointing to his father's water bottle during a break in play while William gave him a sip.

The duke and duchess have made no secret the royal heir is a handful. And his growing mobility will mean the couple are in for an even busier home life.