Novak, Kei advance; Osaka beats Azarenka

The Serb was beaten by Briton Kyle Edmund in the second round of the Madrid Open last week, but turned in a convincing display to see off Dolgopolov in under an hour in Rome, returning deep and controlling play from the baseline. Djokovic plunged to 18th in the latest world rankings released on Monday, but is optimistic he can go deep in this year's tournament, where he finished runner-up last year.

"Today's match encourages me to move forward and hopefully I can get a few more matches in Rome than I have in the last couple months," said the four-times Italian Open champion. Japan's Kei Nishikori, who like Djokovic is making his way back from injury, also got off to a solid start, striking 18 winners en route to beating Spaniard Feliciano Lopez 7-6(5) 6-4. Nishikori will face third seed Grigor Dimitrov of Bulgaria in the second round. Lopez refused to go down without a fight, forcing a first-set tiebreak that Nishikori edged. The Japanese got an early break in the second, but Lopez clawed his way back to at 3-3 before Nishikori broke again and held his nerve with a flawless service game to seal victory.

"Luckily I (won the) first set and after that I was more confident," Nishikori said. Spain's Pablo Carreno Busta, the 10th seed, was pushed to three sets by hard-hitting American Jared Donaldson, but held on before flattening his opponent in the decider to win 6-4 3-6 6-0.

Carreno Busta will face Donaldson's compatriot Steve Johnson in the second round. Germany's Philipp Kohlschreiber was forced to play two tiebreaks before edging out Russia's Karen Khachanov 7-5 6-7(7) 7-6(6) in an encounter that stretched over three hours.

Kohlschreiber came from behind to win the first set, but passed up on an opportunity to serve out the match in the second, allowing the Russian to force the decider. The two went toe-to-toe in the third set, with neither able to gain a decisive advantage until Kohlschreiber got his nose in front in the tiebreak and converted his third match point.

Rising Japanese sensation Naomi Osaka eased into the second round of the Italian Open on Monday with a 6-0 6-3 victory over former world number one Victoria Azarenka, on a day in which local favourite Roberta Vinci called time on her career.

Roberta Vinci was beaten 2-6, 6-0, 6-3 by Serbia's Aleksandra Krunic in an emotionally charged encounter in front of a packed crowd on Court Pietrangeli. The 35-year-old had announced her intention to retire after the tournament, and her exit brings down the curtain on her 20-year career in the sport.