Wahab Riaz's magnificent spell

Australia's Shane Watson and Pakistan's Wahab Riaz have been fined for breaching the International Cricket Council's Code of Conduct.

Watson has been fined 15 per cent of his match fee while Wahab was fined 50 per cent of his for actions the ICC match referee Ranjan Madugalle said "crossed that fine line between intense competition and unacceptable behaviour".

The pair had a running battle during Australia's run chase in their six-wicket win in their World Cup quarter-final at Adelaide Oval on Friday night.

Wahab applaud's Watson's grit // Getty Images

Watson was fined for "conduct contrrary to the spirit of the game" while Wahab, who finished with 2-34 from nine overs, was caught by a different charge for "using language or a gesture that is obscene, offensive or insulting".

The pair were engaged in a memorable battle of hostile fast bowling early in the innings, when Wahab fizzed numerous bouncers past the ears of the Australia allrounder in a fearsome six-over spell that also saw him collect the wickets of David Warner and bounce out Michael Clarke.

That spell saw Wahab follow through after his deliveries close to Watson, eyeballing his opponent who wordlessly returned his stare in one of the World Cup's great pieces of theatre.

Watson smiles at Wahab late in the game // Getty Images

The charges stemmed for an altercation much later in the match, after the 33rd over, when Watson spoke back to Wahab after he had followed through after another bouncer.

Quick Single: High praise for Wahab's 'nasty' spell

"It was an enthralling contest between Shane and Wahab, but in the closing stages of the match both players crossed that fine line between intense competition and unacceptable behaviour, and this resulted in the sanctions," Madugalle said.

Wahab bowled a fiery spell to Watson and was unlucky not to claim the allrounder's wicket when a top-edged pull shot slipped through the fingers of Rahat Ali on the fine leg boundary.

Watson took advantage of the let off and posted a match-winning innings of 64 not out as Australia chased down Pakistan's total of 213 with 97 balls to spare.

Wahab was involved in the action throughout the match. A photo captured by cricket.com.au showed the paceman engaging in verbals with the Australian team prior to the teams entering the field of play for the pre-match national anthem ceremony.

Finch and Wahab chat before play // cricket.com.au

After the match, the Pakistan paceman revealed he had been inspired by chat from Watson during his time at the crease.

"When I was batting Watson just came up to me and said, 'Are you holding a bat?' And that was going through my mind," Wahab said.

"I let him know that even he is having the bat, but he couldn't touch the ball.

"I know that nowadays, he's not good on the short ball. It was a plan of myself that we discussed in the team meeting."

Watson and Wahab embrace after the match // Getty Images