The fourth seed's last competitive match was a quarter-final defeat to Roger Federer at Wimbledon after which he injured his knee when he slipped trying to jump into the sea from a yacht off the coast of his native Croatia.
The injury ended a purple patch for the 22-year-old during which he won the second ATP title of his career at 'sHertogenbosch, reached the last eight at successive Grand slams and rose to a career-high seventh in the world rankings.
Back on court in Beijing on Tuesday, the tall right-hander made the most of Lopez's frequent errors and flapping backhand to take the first set with some ease.
But Lopez fought back to take the second by converting his second break point when Ancic put a forehand wide after a mammoth seventh game.
Ancic responded by breaking the Spaniard in the second game of the third set and then saved three break points to win the next game and clinched the match with an unreturnable serve.
Tuesday’s results:
First round: 1-Ivan Ljubicic (Croatia) beat Go Soeda (Japan) 6-4, 6-2; 4-Mario Ancic (Croatia) beat Feliciano Lopez (Spain) 6-3, 3-6, 6-3; Alexander Peya (Austria) beat Ramon Delgado (Paraguay) 6-4, 6-2; Luka Gregorc (Slovenia) beat Yu Wang Jr (China) 7-6 (8-6), 6-3; Satoshi Iwabuchi (Japan) beat Nathan Healey (Australia) 6-1, 7-6 (7-5); Michael Berrer (Germany) beat Gouichi Motomura (Japan) 7-5, 6-4; 7-Ivo Karlovic (Croatia) beat Mikhail Ledovskikh (Russia) 6-2, 7-6 (7-2).
CZINK SINKS HANTUCHOVA
DENPASAR (Indonesia): Daniela Hantuchova became the first big-name casualty at the Bali International when the fifth-seeded Slovakian slumped to a 7-5, 6-2 first round defeat against Hungarian left-hander Melinda Czink on Tuesday.
Hantuchova held the upper hand in the early stages to build a 5-2 lead before squandering three set points on Czink's serve.
The missed opportunities seemed to derail the Slovakian and she dropped her next two service games before Czink then held off a break point when leading 6-5 to serve out for the opening set.
Three breaks of serve at the start of the second set left Czink leading 2-1 and a fine backhand drive gave her a further break for a decisive 5-2 lead.
Results:
First round: 8-Severine Bremond (France) beat Trudi Musgrave (Australia) 6-2, 6-2; 3-Lindsay Davenport (US) beat Galina Voskoboeva (Russia) 7-5, 6-1; Akiko Morigami (Japan) beat Natalie Grandin (South Africa) 6-2, 6-1’ Sandy Gumulya (Indonesia) beat So-Jung Kim (South Korea) 7-5, 6-4; 9-Aiko Nakamura (Japan) beat Suchanan Viratprasert (Thailand) 7-6, 6-4; Melinda Czink (Hungary) beat 5-Daniela Hantuchova (Slovakia) 7-5, 6-2; Hana Sromova (Czech Republic) beat Junri Namigata (Japan) 6-3, 6-1; Erika Takao (Japan) beat Vivien Silfany (Indonesia) 6-3, 6-1; 6-Marion Bartoli (France) beat Ayu Fani Damayanti (Indonesia) 6-1, 6-0; Casey Dell'Acqua (Australia) beat Lavinia Tananta (Indonesia) 6-0, 6-2; Angelique Widjaja (Indonesia) beat Sunitha Rao (US) 6-3, 6-4.—Reuters