Black Eyed Peas star stunned two struggling U.S. families on the verge of losing their homes on Monday (10May10) by revealing he'd paid off their mortgages.
The generous hitmaker agreed to give his financial advice to the two families invited to appear on pal Oprah Winfrey's talk show, but when he realised just how much debt the family of eight and the single mother were in - due to the economic collapse - he offered to dig deep and give them the cash they needed to survive instead.
The cash amounted to more than $350,000 (£218,750).
The two families had no idea they would be meeting a pop superstar on Oprah's stage - or that he'd be solving their immediate financial problems.
He and Winfrey both fought back tears as the grateful folks hugged each other and sobbed.
Speaking of the reasons behind his generous cash gift to complete strangers, the I Gotta Feeling singer said, "I'm OK. I don't dream of being mega, crazy rich; I just wanna be able to create, make music and help people.
"Doing this isn't gonna leave a dent in my house... but it could help somebody that really needs it. It's something that means a lot to me."
There was more emotion on Monday's show when showed off home video footage of the day last year (09) when he bought his grandmother a house.
The hitmaker, who was celebrating his birthday on the day he handed his gran the keys to her own place, said, "I told my mom to bring everybody to this house - because we were gonna have dinner - and when they got there, she's like, 'William, whose house is this?'
"My grandmother's been in the projects for 50 years. I can't imagine what she was thinking." also showed Oprah cameras around his old neighbourhood in East Los Angeles.
The rapper/singer also launched his home charity on the show. The fund will help struggling families.