Novak Djokovic returned to action for the first time since becoming a father with a straight-sets win over Philipp Kohlschreiber at the Paris Masters.
The Serb, 27, won 6-3 6-4 seven days after his wife Jelena gave birth to their first child, Stefan.
Djokovic is trying to protect his world number one ranking, with Roger Federer closing in on him following victory at the Swiss Indoors on Sunday.
Federer will open his campaign on Wednesday along with Andy Murray.
The Swiss, 33, faces France's Jeremy Chardy in his opening match and needs to continue his fine run of form in Paris if he is to overtake Djokovic in the standings.