2) Going second, open Fishing Village/watchtower. Opponent opens ambassador/secret chamber. Turn 3, opponent ambassadors his secret chamber, watchtower it to the top of your deck. On your turn, play fv, watchtower, then sc.
Also works in a 2p game, though.
Edit: some more solutions: 3p+: Open tribute/nothing, hit copper/silver from both opponents.
2p: Open tribute/secret chamber, hit great hall/island + any other green or treasure, then secret chamber.