Sia's Cheap Thrills single closing in on Mike Posner for chart top spot
Sia is challenging Mike Posner for this week's number one single, according to the Official Chart Update.
The Australian pop star's latest release, titled Cheap Thrills, has jumped two places to number two in the Official UK Singles Chart.
Cheap Thrills has already given Sia her biggest UK chart hit as a headline artist.
She previously reached the summit as a guest on David Guetta's Titanium in February 2012.
Fifth Harmony, who first found fame on the US version of The X Factor, have fallen to number three with Work From Home.
Lukas Graham's 7 Years is at number four, with Zara Larsson's Lush Life rounding out the top five.
Alan Walker's Faded is one of two tracks set to hit the top 10 for the first time this week, having climbed to number seven.
Joe Jonas-fronted band DNCE has leapt 17 places to number 10 with Cake By The Ocean.
The Vamps are on course to land their seventh top 40 hit with new OMI collaboration I Found A Girl, currently at number 20.
Meghan Trainor is up five places to number 25 with No.
No Money, the new single from Swedish electronic music duo Galantis, debuts at number 32.
Meanwhile, two tracks expected to rise up the chart are Desire by Years & Years ft Tove Lo at number 39 and I'm In Control by AlunaGeorge, which is one place higher.
On the Official Albums Chart Update, The Last Shadow Puppets are set for their first number one in eight years.
The rock group are currently outselling their nearest chart rivals by nearly 5,000 copies, the Official Charts Company has said.
Alex Turner and Miles Kane's second collaborative album Everything You've Come To Expect is expected to become the duo's second chart-topper together.
This follows The Age Of The Understatement back in 2008.
The collection could also be Turner's seventh UK number one album, including five recorded with Arctic Monkeys.
Lukas Graham follow The Last Shadow Puppets with their self-titled album at number two.
The band's first global release features 7 Years, the longest-reigning Danish number one single in UK chart history.
Enduring electronic duo Pet Shop Boys are at number three with Super.
New entry Kentucky from Black Stone Cherry is sitting at number four.
Aled Jones's new release One Voice is at number six, while Japanese metal idol band Babymetal's Metal Resistance is one place below the singer and broadcaster.
Mogwai's Atomic, Weezer's Weezer (White Album) and Sunset Sons' Very Rarely Say Die are at 14, 16 and 18 respectively.
Scene Delete by UK producer Sasha is just a few places behind at number 23.
This week's new entries are rounded out by Explosions In The Sky's The Wilderness, The Heavy's Hurt & The Merciless and Moderat's III .
Finally, after an acclaimed appearance on The Graham Norton Show last week, Raleigh Ritchie's You're A Man Now, Boy re-enters the top 40, jumping up to number 37.