Sixth seeded Tomas Berdych defeated the hard hitting Ivo Karlovic of Croatia in two sets to advance to the quarterfinals at the Shanghai Rolex Masters in China on Thursday.

The 29-year-old Czech overcame 19 services aces from the powerful 6-foot-11 Croatian to defeat Karlovic in two straight sets 6-3 6-4 which lasted just over an hour.

Like Us on Facebook

Berdych collected 90 points by entering the quarters and is now just 45 points behind Marin Cilic in the year-ending ATP World Tour Finals.

Incidentally, Karlovic stunned Cilic in the first round of the tournament, winning in three sets 7-5 2-6 7(7)-6(2).

Karlovic leads all players this year in service aces and has a recorded fastest serve of 156 mph, third on the list of fastest tennis serves of all time with Australian Samuel Groth leading the list.

Berdych will past sixth placer Cilic if he goes on to the semis but has yet to clinch a spot at the prestigious season ending event in London.

The recent China Open finalist Berdych will next face Gilles Simon of France who defeated Tunisian qualifier Malek Jaziri 6-2 6-3 in their 74 minute encounter.

Simon, 29, upset Australian Open champion Stan Wawrinka in the second round thwarting the Polish national of clinching a spot in London.

In other third round action, Spaniard Feliciano Lopez continued his conquest over seeded players as he defeated John Isner of the United States in two sets 6-3 6-4.

Lopez, who ousted Rafael Nadal in their all-Spanish encounter in the second round, will meet Russian Mikhail Youzhny who came back from a set down to win his match against wild card entry Juan Monaco of Argentina 5-7 6-3 6-2.

Youzhny, who will play in his fourth ATP tour quarterfinals, defeated 12^th seeded Ernests Gulbis in the opening rounds while Monaco advanced to the third round after Milos Raonic retired from their match.

TagsTomas Berdych, Ivo Karlovic, Marin Cilic, Gilles Simon, Feliciano Lopez, rafael nadal