South Korea were left with plenty to ponder ahead of this month's World Cup finals after Edin Visca scored a hat-trick to give Bosnia and Herzegovina a 3-1 victory in a friendly in Jeonju on Friday.
The Koreans had been hoping for a win in their final match on home soil before heading to Europe but lacked accuracy in attack and looked fragile with a three-man defence at the back.
Winger Visca gave the visitors a 28th-minute lead but midfielder Lee Jae-sung, rested for Monday's 2-0 win over Honduras, immediately hit back with a cool finish on the back of a rare fluent attacking move from the home side.
Visca again found space down the right of the Korean defence to put Bosnia back in front on the stroke of halftime, though, and lashed home his third in the 80th minute to silence a big crowd at Jeonju World Cup Stadium.
Korea coach Shin Tae-yong will cut three players from his squad before they head to Austria to make their final preparations for the finals, where they face Sweden, Mexico and world champions Germany in Group F.
Australia trounce Czechs 4-0
Australia cruised to a 4-0 win against the Czech Republic on Friday, giving the Socceroos a much-needed confidence boost ahead of this month's World Cup with their first victory abroad in nearly two years.
Australia, headed to their fourth straight World Cup, grabbed the lead against the run of play in the 32nd minute when Robbie Kruse knocked a pass from the far post to an unmarked Mathew Leckie who tapped the ball in.
The victory over a Czech side that failed to qualify for the tournament in Russia was the first for the Socceroos outside Australia since a 1-0 win over the United Arab Emirates in Abu Dhabi in September 2016.
With a lack of goals a problem in Australia's qualifying campaign, Friday's attacking display gives the team's Dutch coach Bert van Marwijk plenty to think about before he pares four players from his 27-man squad by Monday's FIFA deadline.
Andrew Nabbout made his case for a World Cup role by scoring his first goal for Australia in the 54th minute when he won the ball on the right and his low, hard shot into the far corner beat Czech goalkeeper Tomas Koubek.
Leckie and a Jakub Jugas own goal rounded out the win against a Czech side that had started brightly but failed to show much vigour after going behind.
Australia play a final warm-up against Hungary on June 9 before heading to Russia, where they face France, Denmark and Peru in Group C.