Top seed Carlos Alcaraz survived a huge scare against Finland's Emil Ruusuvuori as his defence of the Madrid Open title began with a hard-fought comeback win.
Spain's Alcaraz, who turns 20 next week, overcame a slow start to win 2-6 6-4 6-2 against the world number 41.
Alcaraz is the favourite to win the Masters 1000 event on the clay of Madrid, with Novak Djokovic and Rafael Nadal absent because of injury.
Alcaraz, who won the Barcelona title last week, plays Grigor Dimitrov next.
Bulgaria's Dimitrov, seeded 26th, won 7-6 (8-6) 7-6 (7-2) against France's Gregoire Barrere in his second-round match.