Pharrell Williams looks set to stay on top of the charts - and break through the half-million sales barrier - this weekend, according to the latest sales figures.
The US star hit the big time last year after he was involved in two of the biggest-selling singles of the year - Get Lucky by French electro duo Daft Punk and Blurred Lines with Robin Thicke.
His latest hit, Happy, has sold nearly 496,000 copies, according to midweek data from the Official Charts Company, making it odds-on to hit the 500,000 mark by the weekend.
Pitbull and Kesha are still stuck at number two with Timber, while Avicii's Hey Brother is also a non-mover at number three.
London teenager Elyar Fox is on course for the highest new entry, with Do It All Over Again in at number four.
Other new entries include Shakira and Rihanna with Can't Remember To Forget You and Tinie Tempah's new single Lover Not A Fighter.
Bruce Springsteen is expected to top the album chart with his new release, High Hopes, knocking Ellie Goulding off the top spot.