Novak Djokovic returned from a surprise defeat in Monte Carlo to progress at the Madrid Open but fourth seed Stan Wawrinka lost to old foe Nick Kyrgios.
Top seed Djokovic, 28, eased into round three by beating Croatian Borna Coric 6-2 6-4 in an hour and 18 minutes.
The 20-year-old Kyrgios saw off his Swiss rival 7-6 (9-7) 7-6 (6-2).
Last year, he was given a suspended 28-day ban and $25,000 (£17,250) fine after making lewd remarks about Wawrinka's girlfriend during a match.
World number one Djokovic, beaten by 55th-ranked Jiri Vesely last month, won 85% of points on his first serve against the 19-year-old Coric, who is nicknamed 'Mini Djokovic' because of his playing style.
The Serb plays 15th seed Roberto Bautista Agut on Thursday, while British second seed Andy Murray faces Frenchman Gilles Simon from 11:00 BST.
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