Juande Ramos' Tottenham thrashed relegation rivals Wigan Athletic 4-0 to lift themselves away from the dropzone.
He passed to Jenas to round Chris Kirkland for the second, after 26 minutes.
Darren Bent came off the bench to add the fourth, then Berbatov was denied the goal his work deserved when his effort came off the post.
"We are happy with the scoreline but the thing I'm more happy with is three of the four matches since I've been here have been clean sheets," Ramos said.
"Once you get that clean sheet, players play much better and have more confidence.
"I can't give an opinion of Spurs before I arrived because I didn't see those matches - but my opinion is that a team needs to be attacking well but you need to do well defensively for solidity. You're going to perform better."
Birmingham's defeat meant Spurs climbed three places.
"I'm especially satisfied with the three points because sometimes you can get three points and the teams behind you win, and you don't really go up the table," Ramos added.