Sexy singer-songwriter Bruno Mars has scored his fourth U.S. No.1 single with his latest offering, 'Locked Out Of Heaven'.

The track, which he recently performed on America's Saturday Night Live, has reached the top spot on the Billboard Hot 100 chart.

Tweeting about his commercial success, Mars wrote (December 13): "Wow! This feels incredible #1 song in the Country because of you. Thank you thank you thank you! #UnorthodoxJukebox."

His other U.S. No.1 singles were 'Just The Way You Are', 'Grenade', and his collaboration with B.o.B on 'Nothin' On You'.

Meanwhile, Mars scored a midweek No.1 in the UK albums chart yesterday (December 12) with his new record 'Unorthodox Jukebox' and is currently outselling the No.2 record, which is Michael Bublé's 'Christmas', by 22,000 copies.

Watch Mars' full Radio 1 Live Lounge special below: