Kelly became Reading's third signing of the January window on Saturday when he left Fulham and signed a two-and-a-half-year deal with the Royals.
Reading invited the Republic of Ireland full-back to watch their game against West Brom that afternoon and, for 82 minutes, Kelly must have been thinking he had made the wrong decision.
Brian McDermott's side were 2-0 down and, with QPR having drawn with Tottenham earlier, were bottom of the Barclays Premier League, but late strikes from Jimmy Kebe, Adam Le Fondre and Pavel Pogrebnyak handed the club their most thrilling win of the season.
Given they are three points from safety with 16 games to go, Reading are still among the favourites for relegation, but Kelly thinks the shock comeback will give his new employers the drive they need to climb out of the relegation zone for good.
"After watching the game at the start it was looking a bit grim," Kelly said. "But to be able to come back, hold on, and show that kind of character and fight is exactly what you need to stay in the Premier League.
"That win has put us closer to the other teams. You look at the table and think it's not impossible.
"I am confident we can stay up. After coming here and meeting everyone affiliated with the club you realise everyone is determined to stay in the league. The determination is unbelievable.
"I want to play in the Premier League and I feel confident we are capable of doing that."