Looks like Bind Weed, A nightmare to get rid of and will take over your yard at an alarming rate unless you do something about it. It looks pretty much like an ivy and climbs up other plants fences etc, strangling as it does.IF it is bind weed it needs to be uprooted and burned... a tiny piece of root left in the garden will set the whole thing away again. whatever you do don't strim or cut and leave bits laying around as this will root itself creating even more of a spread. If it's coming from a neighbours garden they need to do something about it also, otherwise it#ll just come back through. They have an extensive root system white string like which snap easily....but it all needs to come out.
I hope it's not bindweed but looks like it to me.
I know exactly what you're talking about and it is a nightmare. We call it Strangleweed. Horrible little vine. This has much bigger flowers and doesn't grow like a vine- more like some sort of gourd. I'll try to put a wider view up.