Newcastle are definitely one of the impressive teams this season. They have lost only one match which was an away one against Liverpool. They are among the best away teams so far. Especially their win over Tottenham was really impressive. Because it was the only point loss for Tottenham in home matches at the same time.
On the other hand Southampton are far worse than Newcastle now. First of all, they are the worst home team statistically. I don't think they can resist Newcastle until the final whistle. Newcastle beat them here last season and they can do this even more comfortably this season considering their effort so far. I expect a Newcastle win and the odd is 1.93 for that.