One of you suggested it may be a Thunbergia. Well, here is the flower that came today and I borrowed my kind friend's Sony Mavica just for that. Hope someone will now hit the nail on the head.
SOLVED: Hope unknown'll be known
Looks like a Thunbergia to me, possible Thunbergia fragrans.
Oh, it was me btw who suggested it to be a Thunbergia =)