ANDY MURRAY continued his quest to reach the season-ending ATP World Tour finals by booking his place in the last eight of the Shenzhen Open in China.

Murray started the week in 11th place in the Race with only the top eight guaranteed a place at the lucrative event at the O2 Arena in November.

His desire to qualify took him to Shenzhen where he began his campaign with a comfortable 6-3, 6-3 win over India's Somdev Devvarman.

Second seed Murray proved a cut above his world No.141-ranked opponent, breaking twice in the first set without reply.

Devvarman rallied to break the Scot in the second but Murray converted both of his own break point opportunities to move through in one hour and 21 minutes.

In the quarter-finals Murray will play Slovakian world No.85 Lukas Lacko, who beat Ricardas Berankis of Lithuania 6-4, 7-6 (7-1).

Top seed David Ferrer suffered an upset as he was beaten 6-3, 6-4 by Serbian qualifier Viktor Troicki.