Dundee United captain Andy Webster helped his team secure an Active Nation Scottish Cup final place with a 58th minute header.
After a short spell at Wigan, Webster only made one appearance for Rangers amid a continued run of fitness problems which restricted him to 10 first-team appearances in three years, half of them coming during a loan spell at Bristol City.
Webster said: "It's been nice just getting the opportunity to play football again in a very good side and a lot of good players.
"When you train with them and play with them you realise they are a good team that can have success. The boys are hungry for success and that has shown recently.
"Any major final is a great showcase for any player."
United started the match nervously as Raith threatened to emulate Ross's shock win over Celtic, but United took control after David Goodwillie's 28th-minute opener.
"I think it definitely gave Raith a boost, they have seen a First Division club beating a Premier League club, and one the size of Celtic are and the quality of players they have," added the 27 year old.
"I'm sure that would have been mentioned to them beforehand.
"We just had to focus on our job and go about our business the way we normally do.
"Getting the first goal probably settled us down and we started passing the ball after weathering the initial storm."