Roger Federer has shaken off his poor recent form with a classy 6-4 6-2 victory over Dmitry Tursunov in the first round of the Olympic tennis tournament.
The Swiss top seed arrived on Centre Court 24 hours later than he had expected because of Sunday's rain but wasted little time dismantling the Russian.
Federer broke serve once to win the opening set and moved up a gear to cruise through the second set.
Before arriving in China for his third crack at Olympic gold, Federer suffered early defeats at tournaments in Toronto and Cincinnati and is still coming to terms with losing his Wimbledon crown to Spain's Rafael Nadal.
Federer, who will lose his world number one ranking to Nadal next Monday, later teamed up with Stanislas Wawrinka to progress in the men's doubles.