McKagan rejoined GNR as a fill-in for bassist Tommy Stinson, who has obligations to play previously scheduled dates with The Replacements this month at the Coachella Festival.

As with his first GNR show in Buenoes Aires on Sunday, Duff handled lead vocals on a pair of covers, including The Misfits' "Attitude" and The Stooges' "Raw Power."

"Thank you and Gracias Paraguay! What a show! GNR," tweeted McKagan after the show, the second of five he'll play in South America this month with the group.