The holders were in a completely different league to the English champions as they dominated the second leg at Stamford Bridge on Sunday just as they had back home in Spain seven days earlier, the final aggregate margin of 8-2 not flattering brilliant Barca.
Matildas captain Kerr was still not ready to return to action after more than a year out with her ACL injury but even the Australian star's presence would hardly have helped the Blues as the silky visitors remained on course for a third straight European crown.
They'll play either record eight-time winners Lyon, managed by Australian Joe Montemurro and featuring star Matilda Ellie Carpenter, or Arsenal, complete with their own Australian trio of Kyra Cooney-Cross, Steph Catley and Caitlin Ford, in the final.
They were playing their semi-final return leg in France later on Sunday, with Lyon 2-1 up from the first leg.Â
Barcelona took their goal tally to a remarkable 44 in this season's competition, ignited by a dazzling first-half solo goal from the world's best woman player, Aitana Bonmati.
The Ballon d'Or winner picked up the ball inside her own half and broke down the right at pace before ripping home an unstoppable shot into the top-right corner from just inside the area.
Barcelona went 2-0 up in the 41st minute when Caroline Graham Hansen found space down the right and picked out Poland captain Ewa Pajor with a fine cross.
Two minutes later, Claudia Pina curled in a superb third as Chelsea continued to be embarrassed.
After the luxury of being able to make changes at the interval, Barca still belatedly took advantage of more poor defending as Salma Paralluelo scored a fourth in the last minute, before Dutch midfielder Wieke Kaptein grabbed a stoppage-time consolation.
It was the end of another European dream for Kerr and Chelsea. They reached the final back in 2021, only to be routed 4-0 that day by Barcelona. Four years on, it felt as if nothing had changed.
