help ! traveling from Seoul to SHANGHAI 4 DAYS -144 VISA STAY - then fly to London.

Hello I have booked my flights and just had a mild freak out

I know you can fly for example
UK - Shanghai - Hong Kong- UK
but can you UK - Seoul - Shanghai - UK
meaning its ok to fly Shanghai- uk and do the transfer (Seoul in this case) previously to arriving in china not afterwards?
so I don't need to fly somewhere in-between like Hong Kong?