Round 4 of the World Chess Olympiad brought a big derby between the top rated Russia and 5th-seeded Ukraine.

Ian Nepomniachtchi put Russia in the lead, but the Ukrainians fought back and with the wins by Ponomariov and Volokitin turned the match in their favour 2,5-1,5.

The 2nd-seeded USA were held to a tie by the solid Czech Republic, but the other favourites fared better. Azerbaijan and China won by 3-1 against Romania and Italy, respectively.

Shahriyar Mammadyarov and Arkadij Naiditsch have won to continue their perfect streak of 4 points from 4 games each. Teymur Rajabov and Rauf Mammadov drew their games.

India defeated Cuba 2,5-1,5 and Netherlands demolished England 3,5-0,5.

Sergei Zhigalko defeated Alexei Shirov to secure a narrow Belarus victory against Latvia. In similar fashion, Tsegmed Batchuluun brought the victory for Mongolia against the higher-rated Croatia.

Aleksandar Indjic put Serbia in lead against Slovenia, but Luka Lenic struck back to even the match. Spain crushed Peru by 3,5-0,5 and Georgia defeated Bulgaria 3-1 with a Jobava win against Topalov on the top board.

Azerbaijan 2 was convincing against IBCA 3,5-0,5, while Azerbaijan 3 lost by the same result to Turkmenistan.

Top round 5 matches are Ukraine-China, Netherlands-Belarus, Serbia-USA, Azerbaijan-India, Slovenia-Czech Republic.

In the Women section the biggest attention was attached to the victory of Dana Reizniece-Ozola, Latvia's top board and also the country's Minister for Finance, against the world champion Hou Yifan. China still emerged on the top with wins of Ju Wenjun and Guo Qi.

On the first table Russia defeated Hungary thanks to Natalija Pogonina's effort on the 4th board. Ukraine was convincing 3,5-0,5 against France, whose top rated player Sophie Milliet took a day off.

India and Israel, as well as Azerbaijan and Romania, exchanged blows but by the end of the day their respective matches were tied.

Azerbaijan and Romania were today matched against each other in both sections. Zeynab Mammadyarova defeated Corina-Isabela Peptan and Cristina-Adela Foisor equalized against Gunay Mammadzada.

Kazakhstan came up top in the clash with Lithuania. Pia Cramling won a nice game to bring Sweden in the lead, but Serbia dominated on the remaining boards for a total 3-1 victory.

Italy narrowly defeated Azerbaijan 2, while Azerbaijan 3 split the match points with Brazil.

Top round 5 matches are Serbia-Ukraine, Russia-Kazakhstan, Israel-Romania, Azerbaijan-Germany, Vietnam-India.