Rolling Stones fans in attendance at the band's May 29 show in Lisbon got an extra dose of legendary rock star magic when Bruce Springsteen joined the band on stage for the evening's performance of 'Tumblin' Dice.'

As noted by the NME, this isn't the first time Springsteen's played 'Tumblin' Dice' with the Stones; he also joined them for the 'Exile on Main Street' classic in December of 2012, during the Stones' gig at the Prudential Center in Newark, N.J. Of course, when you're playing in the Boss' back yard, it isn't all that surprising when he shows up on stage; Portugal is a long way from Jersey, so last night's appearance -- which you can watch via the video embed at the top of this post -- was much more unexpected.

As we previously reported, the Stones recently resumed their world tour following a brief hiatus in order for Mick Jagger to sort things through following the suicide of his longtime girlfriend, designer and model L'Wren Scott. The band is facing down a stretch of summer European dates, after which they're scheduled to head to Australia and New Zealand to make up the shows that were postponed in the spring.

Springsteen, meanwhile, is planning his next move following a lengthy, well-received tour behind his recent 'High Hopes' LP. "I just wanted to get a chance to thank all of the fans who came to all of the shows. We've had incredible audiences in Europe, South America, Africa, down under in Australia and here in the United States," he told E Street Radio before the tour's last show. "Our reach has been greater than it's ever been before, the audiences have never been greater, and we're looking forward to nothing but more in the future."