Arsenal exited the Champions League on Tuesday despite winning their Champions League last 16 second leg clash 2-0 in Monaco but losing on the away goals rule after the tie finished 3-3 on aggregate.
A first-half goal by Olivier Giroud and then Aaron Ramsey 11 minutes from time gave the Gunners hope but desperate defending by Monaco saw them hold on to reach the quarter-finals in front of a for once packed stadium which included celebrities such as U2 frontman Bono.
The other game went right down to the wire but saw last season's finalists Atletico Madrid scrape through 3-2 on penalties over German side Bayer Leverkusen - Stefan Kiessling missing the penalty to settle the encounter.
The match had finished 1-1 on aggregate after Mario Suarez' deflected first-half effort sufficed to give them a 1-0 win in the game itself.
Monaco emulated fellow Ligue 1 side Paris Saint-Germain in eliminating a Premier League giant from this season's competition as PSG knocked out Chelsea also on away goals last week.
Arsenal manager Arsene Wenger was gracious in defeat which ended for another season his ambition of winning the piece of silverware he most desires.
"We knew it would be very difficult to score that many goals," said Wenger.
"We weren't realistic enough in our approach.
"It's not a question of if we deserved to go through but of being realistic and we made too many errors in the first leg.
"At the end of the day, we paid for our performance in the first leg. Monaco were playing at home but didn't have a shot on goal. We were very close but they surprised us in the first match because subconsciously we were too sure of ourselves.
"We have to congratulate Monaco for their place in the last eight as they defended really well.
"In the last three months we haven't lacked in anything except our performance in the first leg.
"We have a superb spirit and great qualities," added the Frenchman, who first made his name as a top level coach at Monaco.
Arsenal skipper Per Mertesacker, who was one of the players singled out for criticism after the first leg debacle, concurred with Wenger.
"The best team went through," said Mertesacker. "Monaco deserved it because they played much better in the first leg.
Monaco vice-president Vadim Vasilyev hailed a great night in the club's history.
"It's a great night for AS Monaco and it's been 11 years since the 2003-04 season when the team reached this level. Arsenal played a great match but we stayed solid defensively although the final minutes were very difficult."
Atletico displayed all their traditional grittiness in the clash with Bayer which produced little of note apart from Suarez' goal - which took a significant deflection off Omer Toprak - in open play.
His effort ended Atletico's goal drought in the competition at just shy of two hours and was the first goal Bayer had conceded in six matches.
Toprak's awful evening ended in suitably disappointing style as his was one of the three penalties Bayer failed to convert.
Fernando Torres stepped up to make it 3-2 for Atletico and poor Kiessling sent his penalty high over substitute goalkeeper Jan Oblak's bar.
Oblak had been unexpectedly called upon midway through the first-half when Miguel Angel Moya suffered an injury.
"I am not a hero," said the 22-year-old Slovenian.
"We are all heroes. All of us who were here in the stadium this evening (Tuesday evening).
"To be honest it wasn't difficult for me to come on and play with such an atmosphere in the stadium."
Leverkusen midfielder Simone Rolfes believed his side should have committed more in search of an away goal.
"After a penalty shoot-out it is difficult to analyse a game. We may not have shown enough courage, but a little luck is also necessary," he said.