Idris Elba welcomes son Winston

Actor Idris Elba attends the 45th NAACP Image Awards presented by TV One at Pasadena Civic Auditorium on Feb. 22, 2014, in Pasadena, Calif.

Alberto E. Rodriguez/Getty Images for NAACP Image Awards

Idris Elba has welcomed a baby boy named Winston.

The actor and girlfriend Naiyana Garth welcomed a son on Thursday. Elba, 41, announced the happy news on Twitter.

" My Son Winston Elba was born yesterday..Truly Amazing :-)" he wrote Friday, adding a photo of the baby's tiny hand gripping his finger.

It's the second child for Elba, who played Nelson Mandela in "Mandela: Long Walk to Freedom" and is also known for roles on TV's "The Wire" and "Luther." He also has an 11-year-old daughter from a previous relationship.