Liverpool were frustrated by 10-man Arsenal in a 0-0 League Cup semi-final first leg on Thursday at Anfield where the visitors defended superbly after Granit Xhaka's early sending off.
Switzerland international midfielder Xhaka was shown a red card in the 24th minute for a high challenge on Diogo Jota at the edge of the area, catching the Portuguese forward in the ribs and denying him a scoring opportunity.
Arsenal manager Mikel Arteta responded by bringing on defender Rob Holding in place of striker Eddie Nketiah, the hat-trick hero against League One side Sunderland in the quarter-finals, leaving Alexandre Lacazette as the lone man up front.
Despite Liverpool enjoying most of the possession, Arsenal kept them out with an impressive performance under pressure and still looked dangerous on the break.
The hosts were toothless without their potent strike pairing of Mohamed Salah and Sadio Mane, who are playing at the Africa Cup of Nations for Egypt and Senegal respectively.
"I would have preferred to score the goal rather than them getting the red card, especially after the game now," Liverpool manager Juergen Klopp told Sky Sports.
"It's a two-leg game and it's halftime and I can't remember one time in my life when I was sitting with 0-0 at halftime wherever it was and thought, 'Oh, we have no chance any more'."
The winners after next week's second leg in London will face Chelsea, who beat Tottenham Hotspur 3-0 on aggregate on Wednesday, in the final at Wembley on Feb. 27.
Arsenal's best opportunity came in the 71st minute when England international Bukayo Saka forced a crouching save from Alisson with the first real shot on target of the game.
Liverpool's Takumi Minamino then missed a golden chance when the Japanese midfielder fired high over the bar from close range in the 90th.
The miss summed up the night for Liverpool, who lacked composure and snatched at chances against opponents dumped out of the FA Cup in the third round at Championship (second-tier)side Nottingham Forest on Sunday.
"There is so much fight in this team and it showed today," said Arsenal defender Ben White, who was man of the match.
"We dug deep and got the result that we needed ... it's hard enough to come here with 11 men and to get one sent off straight away is not good. But absolutely superb from everyone.
"You have to concentrate the whole game and (have) a bit of luck. The result is well deserved. It's nice to defend like that as a defender."
Arteta hailed his players for their fighting spirit.
"We played the game that we had to play, which is not our game," said the Spaniard, whose side picked up a few injuries with right back Cedric Soares taken off after only 12 minutes and replacement Calum Chambers struggling at the end.
Williams strike sees Bilbao past Atletico into Super Cup final
Athletic Bilbao substitute Nico Williams struck late in the second half to give the Spanish Super Cup holders a 2-1 come-from-behind win over LaLiga champions Atletico Madrid in Thursday's semi-final.
Bilbao set up a showpiece clash on Sunday against Real Madrid, who beat Barcelona 3-2 on Wednesday.
After a slow-paced first period in Riyadh's half-empty King Fahd stadium the teams woke up when Atletico went ahead just past the hour with an own goal by Bilbao keeper Unai Simon.
Thomas Lemar's corner from the right was met by the head of Joao Felix whose effort struck the post, only for the ball to hit the back of the diving Simon and cross the line.
Bilbao equalised with another header from a corner as Yeray Alvarez found the net from close range in the 77th minute.
They then piled the pressure on Atletico, whose goalkeeper Jan Oblak made three excellent saves.
But even the outstanding Oblak could not keep out Williams's low shot from a rebound on the edge of the area that went in off the post nine minutes from time.
Atletico defender Jose Maria Gimenez was sent off in stoppage time for a strong challenge on Inigo Martinez.
"I have dreamed of this moment with my brother many times," Williams, young brother of Athletic striker Inaki, told reporters.
"Their goal was a hard blow, but we are as tough as nails and we know how to bounce back. We are prepared for any challenge and now we'll face a tough opponent in Real Madrid. We go all-in and let's hope we win another Super Cup."
Fourth in the LaLiga standings, 16 points behind leaders Real Madrid, Atletico are in a slump and pressure is mounting on their manager Diego Simeone.
"We did not defend well, we have to work and get better," Simeone told a news conference. "We believe in the work we do. We seek to improve. We have to improve... we are lacking the necessary aggressiveness."