Cricket: Nervy time in Williamson household (video, photos)

Brett Williamson was overcome with emotion as he watched his son, Kane, become the youngest New Zealand cricketer to score a test century on debut yesterday.

The 20-year-old scored 131 to help the Black Caps reach 459 in their first innings in the post-lunch session on the fourth day of the first test against India.

Watching Kane pull on his baggy black cap and take to the field in Ahmedabad was a "nerve-wracking" experience for the Williamson family, who watched the test last night from their family home.

"It was very exciting, almost a bit unbelievable but very, very exciting," Mr Williamson said.

"We were extremely nervous ... but we're very proud of him," he said.

The former Tauranga Boys' College player is the youngest of just eight New Zealanders to achieve the feat of scoring a century on debut.

Mr Williamson said his son dreamed about representing New Zealand and had put in the hard yards to turn his dream into reality.

"He's put in an unbelievable amount of hard work ever since he was about 10 or 11. He's always wanted to play test cricket for New Zealand, it was his dream."

From 5pm yesterday, the the Williamson family, minus one, crowded the television to watch the game.

Mr Williamson's wife Sandra, was in another room for the duration of the innings.

"My poor wife couldn't watch," Mr Williamson said.

"In the cricketing world, they're a little superstitious ... and she was in the other room when it started and she said she couldn't come in during the innings so she waited in another room."

When he was dismissed, Mr Williamson said there "might have been a few sneaky tears" but a lot of excitement.

"It's very surreal ... we're all very proud of him."

Mr Williamson said he was yet to speak to his son. After the game, Mr Williamson said they received dozens of phone calls from family, friends and people they did not even know.

"We got calls and texts, some were from people we had no idea who they were. The support from the local cricket community has been great."

After a "horror start" to his international career, Mr Williamson said for his son to hit a century on test debut was the icing on the cake.

"There have been tough times but he doesn't let it worry him too much.

"He's always in control, has a very clear head and is calm under pressure."

- with NZPA