GOLD COAST - South Africa's Chad le Clos romped to Commonwealth Games gold in the men's 50m butterfly on Friday, but his hopes of rewriting the history books were scuttled by Aussie grit and an overloaded schedule. Hosts Australia flexed their muscles on the Gold Coast with five more swimming gold medals, including a clean sweep in the women's 100m butterfly.

Meanwhile, England's Olympic champion Adam Peaty limbered up for the defence of his Commonwealth 100m breaststroke crown with a Games record of 58.59 seconds in the semi-finals, despite rain falling at the outdoor venue. Four-time butterfly world champion le Clos took full advantage of title-holder Ben Proud's absence to win in 23.37 seconds.

It puts swimming's pin-up boy five medals behind shooters Mick Gault and Philip Adams, who lead the all-time Commonwealth Games tally with 18. Le Clos finished behind world champion Proud in Thursday's heats but the Englishman was disqualified for a false start, gifting the South African an opportunity he gleefully seized.

Dylan Carter took silver for Trinidad and Tobago, three-tenths back, with fellow South African Ryan Coetzee claiming bronze in 23.73. "If Ben Proud had been in the final he would have won for sure," said le Clos after his first major 50m long course title. "I don't make excuses," he added about his failure to overtake Gault and Adams. "I'm only 25 years old, it's my third Games -- I'll get the record, so there's no problem."

His tilt at history ended in the 200m freestyle and the 4x100m free.  There was no repeat of his surprise Rio Olympic silver in the 200m freestyle for le Clos, who faded badly as Australian Kyle Chalmers romped to victory.

Olympic 100m champ Chalmers touched in 1:45.56 as fellow Aussie Mack Horton pinched silver in 1:45.89 from lane one, a day after adding the Commonwealth crown to his Olympic title in the 400m. "I knew I had a bit to give in that last 50," said Chalmers. "It's awesome to go one-two with one of my best mates."

Duncan Scott (1:46.30) took bronze for Scotland as le Clos ran out of steam after a blistering start to finish seventh, dashing his hopes of overtaking Gault and Adams at these Games. "It's the lactic acid that you can't flush out," said le Clos after his quick turnaround. "I wanted to go out hard and kill the race, but I felt like lead in the last 20m and when I saw Kyle Chalmers going past, and I nearly grabbed his leg!" Chalmers returned to anchor Australia to victory over England by two and half seconds in the 4x100m freestyle, giving the home swimmers a total of seven gold medals after two days.

"Everyone is beatable," insisted Peaty, despite not having been beaten at the 100m breaststroke in four years. "But I want to defend my titles and that's what I've come here to do."

Elsewhere, Sarah Vasey took down favourite Alia Atkinson to snatch a shock gold in the 50m breaststroke, leaving the Jamaican flag-bearer with silver for the second successive Games. Australia's Clyde Lewis won the men's 400m individual medley before Mitch Larkin triumphed in the 100m backstroke and Emma McKeon led an Aussie one-two-three in the women's 100m fly ahead of Madeline Groves and Brianna Throssell.

Games champion boxer 'bitten' in ugly opening bout: New Zealand boxer David Nyika alleged that his opponent bit him twice in an "ugly" fight as he launched his bid for a second Commonwealth Games gold on Friday.

The 22-year-old heavyweight defeated Yakita Aska of Antigua and Barbuda 5-0 on Australia's Gold Coast, but said the 91kg bout was far tougher than the scores suggested. "It's probably the closest fight I've had. A little bit rugged, but a perfect start to a long tournament," said Nyika, who won 81kg gold at Glasgow 2014 as a teenager.

"When they don't want to win, they want to survive, it's tough. I copped a couple of bite marks, a couple of low blows. It's a tough fight. He bit me in the end, but that's the sport we're in. Fair play to him: it's kill or be killed."

There was no immediate response from Aska to the allegation, but the 28-year-old said: "He is one of the best. He won gold at the last Commonwealth Games so it was a bad draw for me. "He is a very strong kid."

Nyika, who will face Cameroon's Christian Ndzie Tsoye in Tuesday's quarter-finals, repeated the biting claim later on Instagram, when he joked: "Don't worry guys, I've had my tetanus shots."