Paul McCartney and Ringo Starr Reunite in London to Play Beatles' Hits

Paul McCartney and Ringo Starr are getting back to where they once belonged ... onstage together in the UK!!!

The Beatles stars made their surprise reunion on Thursday night at the O2 Arena in London, all apart of McCartney's "Got Back" tour, which has gone across Europe and Latin America.

McCartney introduced his former bandmate as, "The one and only Mr. Ringo Starr!" Needless to say, the crowd went absolutely wild.

The two icons, now in their 80s, gave a warm embrace and said it was time to rock!

The duo went on to perform classic Beatles hits like  "Sgt. Pepper's Lonely Hearts Club Band" and "Helter Skelter."

Starr ended his cameo with a short and sweet message, "I've had a great night and I love you all. Thanks to this man."