Balde Keita came off the bench to fire Lazio to a fortuitous 1-0 victory over Bayer Leverkusen in Tuesday's Champions League play-off.
Stefano Pioli's men were pressed relentlessly by the German visitors in the first leg at the Stadio Olimpico, who went from strength to strength as the match fizzled by with exciting pace.
Minutes after Hakan Calhanoglu was denied a goal with a brave - but controversial - offside decision, Lazio pounced against the run of play late in the second half via Keita's pace and precision finish.
Leverkusen - fresh from opening their Bundesliga campaign with a win over Hoffenheim - were standoffish in the opening salvos as they struggled to deal with Antonio Candreva's dangerous, darting dribbles.
But the momentum was against the hosts by the time a hopeful long ball was lobbed over Lazio's backline in the 24th minute. Lazio goalkeeper Etrit Berisha was caught napping and Heung-Min Son was only prevented from scoring by superb tracking back from centre-back Mauricio.
Sixty seconds later, both teams were cursing each others' woodwork. Lars Bender's 25-yard strike smashed the post, then the hosts counterattacked and Miroslav Klose showed agility which belied his 37 years of age to wriggle past Bernd Leno and ricochet his shot off the post from an acute angle.
Heavy pressing from Roger Schmidt's visitors left Lazio struggling to retain possession and caused frustration to build for the home fans - some of whom are alleged to have been told to cut out racist chants towards Leverkusen's black players by referee Jonas Eriksson.
Their frustration would have turned to apoplectic rage had Hakan Calhanoglu's outrageous effort from beyond the halfway line been on target, but instead Berisha's desperate scrambling back to his goalline was unnecessary as it flew into the sidenetting.
Lazio withdrew Klose at half-time and substitute Keita had an immediate impact when he was slotted through on goal by Felipe Anderson, but the forward was thwarted by a perfect tackle by Jonathan Tah.
The second half continued to crackle and, with 60 minutes on the clock, Calhanoglu rocketed a 20-yard free kick over the wall straight at Berisha, who palmed it away to safety.
Keita had another half-chance to put the Biancocelesti muscled past Tah following a failed clearance, but his rushed effort was spooned high and wide.
Leverkusen then bombarded Lazio's goal with two ever-so-close efforts – first substitute Admir Mehmedi drove agonisingly wide after a wonderful dribble, then Calhanoglu forced another free kick save from the increasingly-busy Berisha.
Calhanoglu finally thought he had put the Bundesliga side ahead, but the assistant referee made a brave decision to call it offside as the Turk's shot struck Kiessling on the way towards goal, who was judged to have two players between him and the goalline.
Against the run of play, it finally came off for Keita in the 77th minute when he left Jonathan Tah in the dust and buried his strike in the bottom corner, skidding off the inside of the post into the back of Leverkusen's net.
Leno had to prevent the scoreline from looking even better for the side who finished third in Serie A last season, sprinting off his line to save Keita's strike from point-blank range then pouncing on the loose ball.