Though they didn't have Dio then, I saw Deep Purple in '85.
Also saw Rainbow, again without Dio, in '82/'83/?
I saw Dio at the Worcester Centrum on a Halloween night...an amazing show! Can’t remember who opened...not that it mattered. Also saw Rainbow in a small upstate NY theater from the SECOND row (Bonnet was the lead on that tour). But the big bonus was the opening act; Gamma with Ronnie Montrose on lead guitar. Blackmore and Montrose on the same bill? To die for.
Almost forgot...Deep Purple and post-Paul Rodgers Bad Company in St. Louis circa 1986...