World number one Novak Djokovic went down to a shock defeat by Alejandro Davidovich Fokina on his return to the ATP Tour at the Monte Carlo Masters.
Djokovic was playing in his first tournament since February after missing the US hard court swing because of restrictions over his Covid-19 vaccination status.
Davidovich Fokina won 6-3 6-7 (5-7) 6-1 to reach the third round.
Djokovic had his serve broken nine times by his Spanish opponent.
It is the first time the 34-year-old Serb - whose last match was a quarter-final defeat in Dubai - has lost an opener at a tournament since 2018.