"Who's That Girl" and his following single "Don't Worry Be Happy". Reception Critical response The Daily Telegraph music editor Kathy McCabe wrote, "This one has one of those choruses which will be on a continuous loop in your head all day. [....] But this isn't one of those throw away tracks artists stick on a best-of album; not only has it reached the upper echelon of the Australian charts but it has a good shot at breaking him overseas." In a review of Twenty Ten Jamie Horne of The Border Mail said, "the dancefloor-ready "Who's That Girl" with US rapper Eve should make it clear that the former 'Fro' is not that uncool after all". Chris Havercroft from X-Press Magazine wrote, "It is the dancefloor where Sebastian does his most damage and when teaming up with rapper Eve for new single Who's That Girl he shows his knack for targeting his audience". Commercial performance "Who's That Girl" debuted on the ARIA Singles Chart at number 11, and reached number one in its fifth week, Sebastian's fifth of six number one singles in Australia and Eve's first. Sebastian is currently the only Australian male artist in Australian music history to achieve six number one singles, and he is third overall for all Australian acts. Only Kylie Minogue and Delta Goodrem have achieved more. It was also Sebastian's seventh of 12 top ten singles in Australia. "Who's That Girl" spent ten weeks in the ARIA top ten, including two non-consecutive weeks at number one. It stayed in the ARIA Top 50 for 19 weeks, spending 37 weeks in total in the ARIA Top 100. "Who's That Girl" became the second highest selling Australian artist single of 2010 within six weeks of release, and was also the fifth highest selling Australian artist song in 2011. It reached 5× platinum certification in September 2014. "Who's That Girl" won the Highest Selling Single ARIA and Sebastian was nominated as "Most Popular Australian Artist" in the 2011 ARIA Music Awards. "Who's That Girl" debuted at number 16 on the New Zealand Singles Chart, and reached number one in its eleventh week. It was Sebastian's fourth New Zealand top 10 single and second number one there. It received platinum certification from the Recording Industry Association of New Zealand (RIANZ). Accolades "Who's That Girl" was shortlisted for the APRA Song of the Year in 2011, Sebastian's third song