Serena Williams attended an event for lingerie and sports bra brand Berlei on Thursday, the day after the world No 1 was announced as the top seed for the Australian Open.
Williams, who is the face of Berlei, took centre-stage in a TV advertising campaign for the brand that aired for the first time on Monday, a week before the tournament kicks off.
And Williams - who was pictured showing off one of the bras - joined models at the event in Melbourne, where the sportswear range was put to the test with a series of exercises.
VIDEO Scroll down to watch Serena Williams stars in Berlei bra advert
Williams takes the microphone on stage as she addresses the crowd at the event
The word No 1 fronted a TV advertising campaign for the underwear brand, which aired on Monday
Williams watches on as models test out the underwear while playing basketball
Williams, who has been seeded first for the Australian Open, chats on stage with one of the models
Speaking earlier this week about her involvement with Berlei Williams said: 'My mom first discovered Berlei while on a trip to Australia almost 10 years ago and I have been wearing their bras ever since – for every tennis match without fail.
'So when the brand approached me to work with them on their latest campaign for 2015, I jumped at the chance.
'I had such a great time shooting my very first TV commercial for the brand, it's such an exciting campaign that I'm very proud to be part of.'