The DJ's track climbed from last week's runner-up spot to finally achieve pole position, finishing a respectable 9,000 copies ahead of midweek number one 'Alone Again' by Alyssa Reid, who instead settles for the second place.
Speaking of collaborating with Sia, Guetta told the Official Charts Company: "Working with pure talent is all I crave. When Sia wrote 'Titanium' on my beat and laid the vocal it was intended to be for another singer.
"But the emotion and quality couldn't be beaten. To be number one with her is a special moment."
Third place this week goes to 'Somebody That I Used To Know' by Gotye and Kimbra, who rise from last week's seven and just a fortnight ago were flagging at 21.
Last Sunday's number one 'Twilight' by Cover Drive is shunted down to six and Rizzle Kicks also slip down the digits with 'Mama Do The Hump', which is at seven from its previous finish of four. Meanwhile, Lana Del Rey sneaks into the Top 10 at nine with 'Born To Die', up five places following the release of her chart-topping album of the same name.
Also climbing is Pixie Lott's 'Kiss The Stars', which is at 11 from last week's 19, while Flo Rida's 'Good Feeling' and 'Earthquake' by Labrinth and Tinie Tempah fall three apiece to 12 and 14 respectively.
Elsewhere, Ed Sheeran's new release 'Drunk' is up a hefty 14 entries to 15, Swedish House Mafia and Knife Party drop from six to 17 with 'Antidote' and Avicii is down four to 19 with 'Levels'.
Coldplay round out the top 20 with 'Paradise', down three from last week's 17, and Christina Perri just misses out on a return to the upper entries with 'Jar Of Hearts', which is up 15 to 22 in its 36th week on the chart.
Source: Official Charts Company
> This week's albums chart