The Magpies failed to produce a single shot on target as their wait for a first win of the season stretched into November, though the stalemate was enough to move them off the bottom on goal difference.
Newcastle have failed to win in any of their opening 10 league games for the first time since the 1898-99 season, but Benitez expressed satisfaction with his side's performance given the situation in which they entered the game.
"I think we have to consider the circumstances, going away from home at the bottom of the table, getting a clean sheet and a point, you have to consider this more positive than negative," Benitez said.
"They pushed hard in the second half so we did well to keep our clean sheet.
"A little bit better possession sometimes could make a difference for us to create more chances. The positive thing for me is that the team was working really hard, you could see the team spirit, you could see the team fighting until the end in a difficult situation until the end.
"At this point it is more important to take the positive rather than the negative."
Southampton boss Mark Hughes felt anxiety in front of goal cost the Saints what would have been a deserved win, Mohamed Elyounoussi, Mario Lemina and Shane Long having the best chances to settle matters in their favour.
"We were the side that was trying to win the game over the 90 minutes," said Hughes. "I thought that we had the better chances. I don't think Alex McCarthy has had a shot to save over the whole 90 minutes.
"We wanted three points and I felt the performance deserved that but it's back-to-back clean sheets, and that's something we've been working on just to tighten up our defensive platform which will allow us to be a little bit more confident at the top end.
"Clearly we've got a little bit of anxiety in our finishing at times, I think sometimes we snatch at things, we maybe take a shot when an extra pass [is needed], that's understandable because we've had a number of games at home where we haven't got maximum points and at times we just displayed a little bit of that anxiety in our play."