Dimitrov, Kyrgios advance as Sock is beaten in Madrid
The seeds were largely comfortable at the Madrid Open, with Grigor Dimitrov and Nick Kyrgios among the winners.
Grigor Dimitrov and Nick Kyrgios were among the first-round winners at the Madrid Open as Jack Sock bowed out.
Dimitrov, the 12th seed, was tested before getting past German Philipp Kohlschreiber 7-6 (9-7) 6-4 on Monday.
The Bulgarian advanced in one hour, 48 minutes on what was a relatively good day for the seeds in Spain.
Despite battling a groin injury, Kyrgios claimed a 7-6 (7-1) 6-4 win over Marcos Baghdatis.
The Australian, a quarter-finalist at the ATP 1000 event last year, sent down 14 aces and did not face a break point.
Only two seeds departed on the clay, with Sock and Gael Monfils exiting.
Sock, who held an impressive 20-6 win-loss record this year heading into the event, was a shock 6-4 0-6 7-6 (7-4) loser to Nicolas Mahut.
In a rollercoaster all-French clash, Monfils went down to Gilles Simon 0-6 6-0 7-6 (7-0).
Czech 11th seed and 2012 runner-up Tomas Berdych encountered few problems on his way to a 6-4 6-4 win over qualifier Denis Istomin.
Jo-Wilfried Tsonga needed almost three hours to overcome Andrey Kuznetsov 7-6 (7-5) 6-7 (5-7) 7-5.
Meanwhile, Feliciano Lopez was too good for Ernesto Escobedo 6-4 6-4, David Ferrer beat Mikhail Kukushkin 2-6 7-6 (7-1) 6-4 and Florian Mayer claimed a 7-5 7-5 win over Marcel Granollers.
Pablo Cuevas battled past Thomaz Bellucci 7-6 (7-2) 4-6 7-6 (8-6), Jared Donaldson recorded a 7-5 6-3 win against Adrian Mannarino and Robin Haase beat Daniel Evans 7-5 6-2.
Marius Copil saved two match points to win a battle of wildcards 7-6 (8-6) 4-6 7-6 (11-9) over Guillermo Garcia-Lopez.