LB - but I totally got mixed up and thought it was the Pantera/Suicidal Tendencies night! Doh! Don't mind LB but a like Pantera and Suicidal a lot more!
Oddly enough one of the previous times I saw Metallica Limp Bizkit opened for them too

(Summer Sanitarium at Candlestick Park 2003) Openers were:
Limp Bizkit
Linkin Park
Deftones
Mudvayne
Talk about Nu!