Brentford reached their first League Cup semi-final with a shock 1-0 win against Newcastle, while troubled Arsenal prepared for their last eight clash against holders Manchester City on Tuesday.
Brentford, fourth in the Championship, upset Premier League side Newcastle thanks to Josh Dasilva's second-half goal in rain-lashed west London.
Thomas Frank's team had already knocked out West Bromwich Albion, Southampton and Fulham en route to the quarter-finals. Their fourth Premier League scalp took them into their first ever major domestic cup semi-final.
Badly hit by an outbreak of the coronavirus recently, this was another bitter blow in a frustrating season for Newcastle, who were hoping to reach their first domestic semi-final since the 2004-05 FA Cup.
The Magpies remain without a major domestic trophy since the 1955 FA Cup.
With Newcastle winless in their last two Premier League matches, boss Steve Bruce will be under fire from angry fans after the latest cup embarrassment for his club.
Newcastle striker Callum Wilson forced a good save from Luke Daniels early on with a powerful shot from an acute angle.
The Bees were inches away from taking the lead when Dasilva's low cross reached Saman Ghoddos, but the Iran winger's miscued effort looped onto the crossbar.
Ryan Fraser's dipping strike was tipped over by Daniels before the interval.
But Frank's side never looked overawed against and gained their reward in the 66th minute.
Canos pulled his cross back into the path of Dasilva and his volley flashed past Newcastle keeper Karl Darlow.
In Tuesday's other quarter-final, Manchester City can inflict more misery on struggling Arsenal.
Arsenal have lost five of their last seven Premier League games and are 15th in the table, making this their worst start to a season since 1974-75.
Their latest defeat came at Everton on Saturday, sparking talk of dressing room unrest amid reports Gunners manager Mikel Arteta could be in danger of the sack if Arsenal's wretched run continues.
Arteta, whose club last won the League Cup in 1993, believes beating City would be a springboard to a successful second half of the season.
"This is what we want to use it for because it's a competition we want to try to win," said Arteta, who worked as Pep Guardiola's City assistant before joining Arsenal 12 months ago.
City are unbeaten in their last eight games in all competitions -- conceding just one goal in that period.
But they still trail eight points behind Premier League leaders Liverpool after an inconsistent start to the campaign.
Guardiola's men, who have found goals hard to come by in the absence of the injured Sergio Aguero, have won the League Cup for the last three seasons and are bidding to become the first team to win it four years in a row since Liverpool from 1981 to 1984.
On Wednesday, Everton host Manchester United and Tottenham visit second tier Stoke.