Ciro Immobile fired Lazio towards a first Champions League quarter-final in nearly a quarter of a century in Wednesday's 1-0 win over Bayern Munich which plunged their troubled opponents even deeper into crisis.

Italy forward Immobile slotted home the last 16, first leg's decisive goal from the penalty spot in the 69th minute in Rome to pile pressure on Bundesliga champions Bayern, who risk having a disastrous season by their own exalted standards.

The spot-kick was won by Gustav Isaksen who was clattered by Dayot Upamecano with a rash tackle which earned the France defender a red card and left Bayern a man down for the final 20 minutes.

Immobile's strike came days after he netted his 200th Serie A goal and allowed a raucous Lazio home crowd to dream of a first quarter-final in Europe's top competition in 24 years.

"We prepared for this match so that we could give Bayern a game. Even if we'd only had a 10 percent chance the team would have given everything on the pitch," said Ciro Immobile to Amazon Prime Video.

"We wanted to give our supporters a good night and I think we've done that."

Lazio won the Italian title the last time their reached the quarter-finals in 2000, when they fell to Valencia in the last eight.

And in order to emulate that star-studded team which featured the likes of Juan Sebastian Veron, Marcelo Salas and Sinisa Mihajlovic, Maurizio Sarri's side still need to hold out in Bavaria next month.

However Bayern are a club in a slump and a toothless display in the Italian capital in which they didn't have a single shot on target will do nothing to help embattled coach Thomas Tuchel.

Tuchel, who described his side's performance as "a little bit slapstick", denied that he is concerned for his future even though Wednesday's defeat came after a 3-0 thumping at Bayer Leverkusen on Saturday which left Bayern five points off the pace in the German title race.

The Champions League looked like Bayern's last chance at a trophy this season but Immobile put those hopes in serious doubt.

Bayern's 'tough week'

"We had a good first half, we were the better team, we were completely dominant, we had the chances and we lost our rhythm and belief in the second half. I don't know why," said Tuchel.

"With this performance we did everything to lose this game which was completely in out hands."

Star striker Harry Kane admitted Bayern were suffering a "really tough week".

"We're in a difficult spell. We have to fight. We have to turn it round. We have big games and big things to fight for," Kane told TNT Sports.

"We're not out of it, we will never give up. We just need to turn it around. One game or spark can turn it round."

Bayern were on the front foot for most of the opening period, which was light on clearcut chances and featured only one shot on target.

That effort was a weak Alessio Romagnoli header for the hosts, who were lucky to go into the break level as Jamal Musiala shot just over the bar after a slick passing move on the edge of the Lazio area.

Kane lashed over from close range early on while in the 32nd minute Leroy Sane watched his powerful shot fly just wide after a neat free-kick routine.

But right after the break Bayern had Manuel Neuer to thank after he rushed out to stop Gustav Isaksen for giving Lazio the lead after being brilliantly put through by Luis Alberto.

And after a long spell of ineffective Bayern possession, Immobile punished the away side with his 20th goal of the season, won by Isaksen when he was upended by Upamecano.

Bayern were left a goal and man down and from that point had an even harder time threatening the well-organised home defence, allowing Lazio to hold out for a famous win.