Rangers beat Sunderland 3-1 on Saturday to claim successive top-flight wins for the first time since December 1995 and move level on points with Reading at the foot of the table, four points behind next Saturday's opponents Villa, who are 17th.
"The lads are really, really buzzing," said Jenas, who spent a spell on loan at Villa Park last season and scored his first Premier League goal since September 2009 against the Black Cats.
"There's that belief now. The games keep getting bigger and bigger. We've got Villa next and that turns into a huge one we shouldn't lose.
"We were seven points off it a couple of weeks ago but I said then that if we can get a couple of wins, people start looking over their shoulders.
"Players think about that in games. It starts affecting their performances. If you are champing on their heels they know they can't relax. That's all we can do.
"We've got a group of players here who firmly believe we can do it. That is our goal now. That is our trophy at the end of the season, to stay in this league."