Ferran 'Coro' Corominas had given Fran Escriba's side the lead in a scrappy first half that was low on attractive football, and Manu del Moral looked to have sealed the points when he doubled their advantage on 66 minute.
However, Colombian forward Osorio scored twice in seven minutes to earn Valladolid a valuable point that not only puts them three points from safety, but also prevents Elche from moving seven points away from them.
And it will help the team's morale, as it is now the third time this season Valladolid have gained a point after going 2-0 down.
A rain-soaked pitch made for a scrappy game played more in the air than on the ground, with the visitors' superior fitness and work rate playing to their advantage.
Neither side had created a clear goalscoring opportunity until Coro broke the deadlock after 34 minutes, the forward scoring from close range after Cristian Herrera had controlled a cross from right-back Cristian Sapunaru.
Manucho had the ball in the net for Valladolid early in the second half but although his effort was ruled offside, it was a sign that the hosts were growing in confidence.
Elche goalkeeper Tono then had to save an effort from Antonio Rukavina, and Alvaro Botia blocked a shot from Jeffren.
However, their revival looked to have been futile when Del Moral rifled home inside the six yard box following a corner.
Valladolid had 24 minutes to find two goals and got the first after five minutes, Osorio shooting high into the net after Manucho had controlled a high ball with his chest.
Goalkeeper Diego Marino then made a vital save to keep Valladolid in the game, sticking out a leg to deny Del Moral.
Osorio made sure his team-mate's heroics were not in vain by heading in the equaliser from a corner, leaping higher than the Elche defenders closest to him to get on the end of Jeffren's cross.
The former Barcelona player had to retire from what was his Valladolid debut just a minute after providing the cross for the goal, nursing a muscular injury.
Juan Iganacio Martinez had already used his three substitutes and so Valladolid had to cling on with a man less for the remaining 10 minutes, but were up to the task.