Liverpool were left frustrated by 10-man Arsenal in the first leg of their Carabao Cup semi-final at Anfield.
Granit Xhaka was dismissed after 24 minutes for denying a goalscoring opportunity.
The Swiss midfielder caught Diogo Jota with a high challenge on the edge of his penalty area as he attempted to cut out Andrew Robertson’s pass.
Trent Alexander-Arnold could not punish Arsenal further from the resulting free-kick.
The visitors produced a resolute defensive display to leave on level terms with Liverpool.
Despite coming under intense pressure it was Arsenal who registered the first shot on target 71 minutes into the contest.
But a poor first touch by Bukayo Saka allowed Alisson to smother the England international’s shot at close range.
Takumi Minamino blazed over the crossbar when faced with an open goal with Liverpool’s best chance of the match in the closing stages.
The second leg takes place at Emirates Stadium next Thursday.
The winner will face Chelsea in the final at Wembley at the end of February, after Thomas Tuchel’s side completed a 3-0 aggregate victory over Tottenham on Wednesday.