Roger Federer recovered from 5-3 down in the final set to beat Philipp Kohlschreiber in the first round of the Gerry Weber Open in Halle, Germany.
World number two Federer, 33, required two tie-breaks to overcome the German 7-6 3-6 7-6 and make a successful start to his grass-court campaign.
The Swiss top seed has seven Halle titles and is preparing for an attempt to win a record eighth Wimbledon crown.
World number six Tomas Berdych faces Victor Estrella Burgos on Tuesday.
Czech Berdych plays his first-round match after French fourth seed Gael Monfils, who faces Czech Lukas Rosol.