Durban, Sep 4 : Australia have issued a warning ahead of the ICC Men's Cricket World Cup with a clinical 3-0 sweep over South Africa in their T20I series, here. The five-time World Cup champions confirmed the series sweep with yet another dominant performance on Sunday as they cruised to a five-wicket victory on the back of a career-best T20I innings of 91 from opener Travis Head, reports ICC. Head was adjudged Player of the Match after he smashed eight fours and six sixes during an entertaining 48-ball stay, as Australia chased down South Africa's decent total of 190/8 with more than two overs remaining. Head was last month named in Australia's preliminary World Cup squad for this year's 50-over showcase and the left-hander showed he could play a big part at the event with his maiden T20I half-century against the Proteas. "It's nice to be back and contributing," Head said. "There's been limited opportunities in this format for a while. I'd been struggling a little bit to find my tempo and how I wanted to go about it at the top." All-rounder Mitch Marsh was named Player of the Series for his 186 runs and the Australia captain could also play a big role in his side's World Cup push in India if he can replicate the hard-hitting form he showed against South Africa. The series was Marsh's first as Australia's new T20I captain and the 31-year-old was thrilled his side could ease to a comfortable series triumph. "I'm really proud of a pretty young group coming over here and winning the series 3-0," Marsh said. "We had a great team effort. We prepared really well, and we took the game on. "We had a bit of luck at times, but as a team we had the mentality of being really positive." While South Africa badly missed the services of pace duo Kagiso Rabada and Anrich Nortje throughout the series, white-ball coach Rob Walter was making no excuses for his side's below-par performances. "There's no running away from it - their batting skill was better than what we had to offer with the ball," Walter said. "We got a hard lesson in terms of not executing our skills. It was an eye-opener for the bowling unit." The teams will now get some valuable 50-over practice ahead of the World Cup when they play a five-match ODI series in South Africa. The first match of that series will be held in Bloemfontein on Thursday. /IANS