Both teams were defensively solid and difficult to break down. I thought both teams did the best they could to break down the other, but both teams defended very well throughout the match.
South Korea have lots of good technical players in their team and have a good, patient, probing approach to playing football. Their counterattacks can be dangerous as well. Luckily for Russia, Son had a bad match, and Park Chu Young started against them, so their attacks weren't that deadly. Lee Keun Ho came in too late as the Korean team started to tire out.
The Russians, without Shirokov, seemed to lose the midfield battle as they had to play two wingers in central midfield. Whilst Fayzulin handled the unfamiliar role in average fashion (okay but still not performing well), Shatov was poor in central midfield. Once Dzagoev came on, Russia were winning the midfield battle. However, the Korean defenders were very good and shut down Kokorin for the whole match.
Both teams conceded because of poor goalkeeping, but that's all good as I'd rather have a 1-1 draw than a 0-0 draw. Belgium will have a tough time breaking down both teams unless both teams try to take Belgium on rather than keep themselves organised.