The tame back pass from John Stones trickled toward Zack Steffen. Just a simple clearance was needed by Manchester City's backup goalkeeper with Liverpool already leading.
One touch controlled the pass. The second touch was ... doing what? The dawdling American just took too long.
Before the ball could behoofed clear, Sadio Mane raced into the penalty area and slid in to nudge the ball over the line.
"It is an accident," City manager Pep Guardiola said. "It happens."
Liverpool moved into a two-goal lead — building on Ibrahima Konate's header — and Mane scored again before halftime with a volley beating Steffen at his near post. A 3-2 victory was secured at Wembley Stadium overnight after withstanding a City comeback with Jack Grealish scoring two minutes into the second half and Bernardo Silva netting in stoppage time.
Their tussle for the English Premier League trophy is far tighter than this FA Cup semifinal suggested, where Liverpool's superiority was clear in the first half before goals from Jack Grealish and Bernardo Silva gave hope of a City comeback.
Their 2-2 draw last Sunday in the league prevented Liverpool from moving into first place, and left City a point in front.
There could yet be a fourth instalment of this rivalry this season in Paris next month if they win semifinals to reach the Champions League final. That would see Liverpool contest three finals in 2022 having already won the League Cup at Wembley.
The strain on the squads meant Liverpool and City made seven changes from their Champions League quarterfinal wins in midweek, and Jürgen Klopp's side had the greater depth to prevail in the heat of London.
"We started very well, we pressed them high and the goalkeeper made the mistake," Mane said. "The performance of the team was fantastic."
CHAMPIONS LEAGUE CHASE
City and Liverpool look sure to qualify for the Champions League again. The rest of the Premier League's top four is more up for grabs, with Manchester United's pursuit helped by Tottenham and Arsenal losing.
Cristiano Ronaldo's hat trick secured a 3-2 victory over Norwich after the last-placed team fought back from two goals down. United moved above Arsenal and into fifth place.
Tottenham is still fourth but only three points ahead of United after Leandro Trossard's goal in the 90th minute gave Brighton a 1-0 win in north London.
Arsenal is on the slide. A fourth loss in five games was inflicted by Southampton with Jan Bednarek sealing a 1-0 win.
Watford slipped closer to relegation after losing 2-1 to Brentford, which moved into 11th place in their first Premier League campaign. Pontus Jansson scored the winner in the fifth minute of stoppage time.
