Daniel Farke's side were moments away from victory at the London Stadium after Ao Tanaka's first-half goal and Dominic Calvert-Lewin's second-half penalty put them in control.

But West Ham staged a stoppage-time rally as Mateus Fernandes reduced the deficit before Axel Disasi's equaliser forced extra-time.

With the score still level at 2-2 after the additional period, Leeds keeper Lucas Perri emerged as their shoot-out hero.

Joel Piroe missed Leeds' first penalty but Calvert-Lewin, Brenden Aaronson, Wilfried Gnonto and Pascal Struijk all converted their kicks.

Perri saved Jarrod Bowen's opening effort for West Ham and also denied Pablo as Leeds won 4-2 on penalties.

It was their second shoot-out victory in the competition this season following their fourth-round success at Birmingham.

Leeds join Manchester City, Chelsea and Southampton in the semi-finals.

The Yorkshire club are in the FA Cup semi-finals for the first time since 1987, when they lost to eventual winners Coventry at Hillsborough.

Leeds have lost on their past three trips to Wembley, in the 2024 Championship play-off final, the 2008 League One play-off final and the 1996 League Cup final.

FA Cup winners for the only time in 1972, Leeds' last victory at Wembley was a 4-3 success against Liverpool in the 1992 Charity Shield.

Their win over West Ham was a welcome lift in the midst of a Premier League relegation battle for both clubs.

Third-bottom West Ham are one point behind fourth-bottom Tottenham with seven games left.

Leeds, four points above the Hammers, face a return trip to West Ham for a potentially decisive clash on the last day of the season.

- Penalty drama -

West Ham boss Nuno Espirito Santo made five changes as he prioritised Friday's vital showdown with bottom-of-the-table Wolves.

Leeds grabbed the opener in the 26th minute thanks to an eye-catching effort from Japan midfielder Tanaka, who cleverly twisted to find space inside the penalty area for a shot that deflected off Disasi and bounced in off the crossbar.

Leeds struck again in the 75th minute after Max Kilman chopped down Aaronson in the area, with referee Craig Pawson changing his decision to a penalty after consulting the pitch-side monitor.

Calvert-Lewin confidently stroked his spot-kick past Alphonse Areola before sprinting to celebrate with 9,000 raucous Leeds supporters crammed behind the goal.

Leeds lost focus in the closing stages, allowing West Ham to stage their remarkable comeback.

Fernandes tapped in the rebound after Bowen hit the post in the third minute of stoppage-time.

Stunned by the decision to play 11 minutes of additional time, Leeds were unable to hold their nerve.

Three minutes after Fernandes' goal, Adama Traore whipped an in-swinging cross into the six-yard box and former Chelsea defender Disasi volleyed home with his out-stretched foot.

Thousands of West Ham fans had already left before Disasi's equaliser and hundreds flooded back in after the goal, although some found the gates shut, leaving them stuck outside for the rest of the match.

With Areola forced off injured late in extra-time, West Ham had to give a debut to reserve keeper Finlay Herrick.

The 20-year-old, who was on loan at non-league side Boreham Wood earlier this season, saved Piroe's penalty.

But there was no fairytale ending for Herrick as Leeds celebrated a semi-final berth almost four decades in the making.