I will take a First Class award ticket from Zurich to Bangkok (180'000 miles)
The routing is ZRH - MUC - SIN - BKK.
I will arrive in Singapore in Lufthansa-First Class then the connection flight to BKK
is in Economy Class with Singapore Airlines at the moment (no open C-Class !).
May i use any lounge at Singapore-Airport in this case ? Sometimes the lounges accept the Inbound flight ticket.

thanx
mac69