Mohamed Salah and Sadio Mane have both marked their first outings in pre-season with a goal as Liverpool came from behind to beat Manchester City by a 2-1 scoreline in the International Champions Cup.
Leroy Sane had given City the lead in Wednesday's clash in New Jersey, but a header from Salah and a last-gasp penalty from Mane - both of whom were introduced after the break - earned Liverpool a deserved victory in the United States.
The opening stages of the game at the Met Life Stadium passed by without incident, but City squandered the chance to go ahead on 13 minutes when Lukas Nmecha was played through on goal, only for the youngster to be denied by Loris Karius.
Liverpool responded with a tame effort from youngster Curtis Jones, but it was City who looked the more likely to take the lead as their youngsters relished the chance to compete on a big stage.
Jack Harrison should have perhaps done better with a volley from the edge of the box when Karius had only half-dealt with a high ball, but Liverpool's superior experience and fitness started to take effect towards the end of the first half.
Jones could have put Liverpool ahead with just three minutes left until half time but, despite getting across his marker to meet Nathaniel Clyne's cross, his header was powered over the crossbar from 10 yards.
City responded through Sane, who was denied by a brilliant save by Liverpool's substitute stopper Caoimhin Kelleher, but it did not take long for the German to get himself on the scoresheet.
Klopp acted by introducing Salah for his first appearance since the World Cup and with his second touch, last season's top goalscorer powered a header past Hart from eight yards after meeting a cross from Rafael Camacho.
Salah could have bagged himself a quick-fire double moments later, only for Cameron Humphreys to get a vital touch at the back post, and the Egypt international then struck the bar from 12 yards after beating the offside trap.
City were still having their moments at the other end of the pitch, but the closing stages soon became about whether Liverpool could force a winner, and they should have done through Mane who could only volley wide from close range after being found at the back post.
The match appeared destined for a penalty shootout but in the third minute of added-on time, Dominic Solanke was barged in the back in the penalty area and it gave Mane the chance to win the game with a well-struck spot kick into the bottom left corner.
LIVERPOOL (4-3-3): Karius (Kelleher 46'); Clyne (Grujic 62'), Gomez (Klavan 46'), Van Dijk (Phillips 66'), Robertson (Morneo 63'); Fabinho (Camacho 63'), Milner (Chirivella 66'), Wijnaldum (Woodburn 46'); Jones (Salah 62'), Lallana (Mane 46'), Sturridge (Solanke 46')
MANCHESTER CITY (3-5-1-1): Bravo (Hart 46'); Garcia, Humphreys, Denayer (Gomes 46'); Bolton (Garre 75'), Zinchenko (Adarabioyo 67'), Harrison (Roberts 67'), Diaz (B.Silva 46'), Foden; Mahrez (Dele-Bashiru 74'); Nmecha (Sane 46')