The 28-year-old has kept six clean sheets in eight appearances since joining Chelsea in a £22 million deal from Rennes in September.
Mendy has now continued his impressive form with Senegal in their latest Africa Cup of Nations qualifier.
Goals from Sadio Mane and Opa Nguette sealed the win for Senegal, but Mendy preserved his nation’s clean sheet with a superb save to deny Marcelo Djalo in the final stages of injury time.
Djalo met a free kick from the left flank with a strong header from six yards out, but Mendy produced a brilliant reaction save from close range to tip the effort over the bar.
After the match, Guinea-Bissau’s head coach, Baciro Cande, praised Mendy for his performance.
‘There were a few minutes left before the end of the first half, unfortunately Senegal benefited from a non-existent penalty, for me there is no foul,’ said Cande.
‘We tried to get back to the score in the second half, we had two or three great chances but we missed them because there was a good goalkeeper in front.’
Mendy is set to be in action once again on Sunday as Senegal face Guinea-Bissau for the return fixture.