Oscar saved Chelsea, interim boss Rafael Benitez and striker Fernando Torres from embarrassment with an 82nd-minute winner in the Europa League last 32 first-leg clash at Sparta Prague which ended 1-0.
Torres, a Â£50million striker now with one goal in 13 games, missed a straightforward effort after 35 minutes and sliced a second-half shot out for a throw-in in another impotent display from last season's Champions League winners at the Generali Arena.
With a stalemate looming and the visiting fans' ire for Benitez and Torres increasing, Oscar came on for Juan Mata and scored with his first involvement, netting neatly following a one-two with Eden Hazard.
After Frank Lampard's early shot from 25 yards was held at the second attempt by Sparta goalkeeper Tomas Vaclik, Hazard twice tried to engineer an opening for Torres, but on each occasion the World Cup winner did not contest good crosses into the six-yard box.
A promising opening from Chelsea, with Marko Marin lively, subsided quickly before an lapse in defence - all too familiar for Benitez of late - nearly presented Sparta with the opening goal after 17 minutes. Right-back Tomas Zapotocny's left-footed diagonal pass over a static defence found David Lafata, who lifted the ball over Petr Cech's goal when he had time to control the ball.
Sparta were finding spaces in and behind the Chelsea defence, but that left them exposed on the counter attack and Chelsea so nearly took advantage after 35 minutes. Marin found Hazard down the left and the Belgian picked out Mata with a cross-field pass. Instead of shooting, Mata teed up his compatriot Torres but his weak toe-poke did not trouble Vaclik.
Lampard shot straight at Vaclik before the break and on the resumption had to make a last-ditch interception to deny Ladislav Krejci a shooting opportunity.
Torres' evening was summed up when he shot right-footed from 20 yards, the ball slicing high and going out for a throw-in.
Mata made way after 82 minutes for Oscar, who had an immediate impact. He injected pace into proceedings and received a return pass from Hazard before clinically netting into the bottom corner.
Torres had an effort saved soon after before Ondrej Svejdik headed over from a corner.