Britain's Andy Murray started the defence of his Madrid Open title with a hard-fought 7-6 (7-3) 3-6 6-1 win over world number 148 Radek Stepanek.
It took Murray two hours and 16 minutes to see off the 37-year-old Czech.
"Not a lot of the match was played on my terms. It was very tough," said the Scot, 28, who will now face 16th seed Gilles Simon or Pablo Carreno Busta in the third round on Thursday.
Earlier Spain's Rafael Nadal beat Russia's Andrey Kuznetsov 6-3 6-3.
Nadal was beaten by world number two Murray in last year's final but the pair are on course to meet in the semi-finals this time.
World number one Novak Djokovic plays Croatia's Borna Coric on Wednesday.
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