Walsall's win takes them into the top six after being second from bottom only a few weeks ago. They have put together a fine run and have only been beaten once in 11 games.
Forest, however, had only themselves to blame for their defeat as they wasted three glorious chances in the first half to have destroyed the Saddlers.
They demonstrated their pace and skill with some impressive football to emerge as the best team seen at Bescot this season with Sammy Clingan often emerging as their driving force in midfield.
Unfortunately their finishing let them down badly in the first half when Nathan Tyson twice wasted fine opportunities to put Forest ahead.
On the first occasion he headed wide at the far post following a cross from Chris Cohen and then blasted his shot high over the bar when challenged by Clayton Ince.
Their third chance occurred a minute before the break when Kris Commons was also wide of the target with his header with Walsall stretched to the limit.
Very little had been seen of Walsall as an attacking force but the Saddlers made Forest pay dearly for their weak finishing two minutes into the second period when the home side took a shock lead.
It was Ricketts who took advantage of a mistake by skipper Ian Breckin. The ball broke loose into the path of the giant Walsall striker and, despite a belated challenge by Kevin Wilson, the former England player blasted home his shot on the run past a transfixed Paul Smith.
Forest took some time to regain their composure as Walsall battled to retain their slender lead. Skipper Tommy Mooney was an inspiration with his battling performance, while their young midfielders, Mark Bradley and Peter Sweeney, gave mature displays.