Sonny Bill Williams: The highs and the lows

SPOTLIGHT: Here are some highs and lows from the sporting career of New Zealand's Sonny Bill Williams, who announced Thursday he is hanging up rugby his boots to concentrate on boxing:

The sweet science

By 2012, Williams had already won a Rugby World Cup and a National Rugby League premiership in Australia, but his boxing career was widely regarded as an indulgent sideshow.

That changed in February 2012 when Williams knocked out American Clarence Tillman, a bigger, heavier and far more experienced opponent, to claim the New Zealand heavyweight title.

Clinching the belt showed Williams possessed genuine talent, though commentator John Davidson said at the time: "If he wants to go really far in the boxing world, he needs to commit to the sweet science permanently."

Sydney-based Williams now intends to do just that after retiring from team sports.

Reviving the Roosters

Williams' ability to switch seamlessly between Rugby Union and Rugby League without any drop in form was best demonstrated when he joined the Sydney Roosters for the 2013 season.

Williams had just won a Super Rugby title with the Chiefs and the Roosters were struggling after failing to win a National Rugby League premiership since 2002.

But Williams galvanised the underperforming team and led their charge to the title. He also inspired New Zealand to the Rugby League World Cup Final, where they lost to Australia, and was named the Rugby League International Federation player of the year.

And the winner is...

Williams sometimes proved divisive, particularly early in his career when his code-hopping antics saw him dubbed 'Money Bill Williams'.

But he won universal acclaim for a thoughtful gesture to a distressed fan after New Zealand's 2015 Rugby World Cup final win over Australia at Twickenham.

An overzealous security guard slammed slightly built teenager Charlie Lines to the ground when he ran onto the pitch after the final whistle.

Williams noticed the incident and stopped performing a lap of honour with his teammates to comfort the 15-year-old and gave him the winner's medal he had just received.

Blame it on Rio

Having tasted success in all his previous sporting sojourns, Williams signed up for New Zealand's Sevens rugby team with his sights set on a gold medal at the 2016 Rio Olympics.

He told AFP before the Games that "to say you're an Olympian: that supercedes everything". But his dream lasted just eight minutes as he limped off during New Zealand's opening match against Japan with a ruptured Achilles tendon.

New Zealand went on to lose the match and exited in the quarterfinals, while Williams never played Sevens again.

Cold shoulder

Williams' most infamous on-field moment was when he was red-carded for a brutal no-arms shoulder charge on Anthony Watson during the second Test of the British and Irish Lions tour in 2017.

The hit resulted in Williams being only the third All Black ever to be sent off, and the first since Colin Meads 50 years previously.

It left the All Blacks a man short for 55 minutes, allowing the Lions to storm home for a come-from-behind victory.

It also arguably shifted the momentum of the series to the Lions, who held on for a draw in the third and final Test, resulting in a tied series.