South Korea head coach Uli Stielike on Thursday praised his players' mental toughness after his squad defeated Uzbekistan 2-0 in extra time to reach the semifinals at the AFC Asian Cup.

Son Heung-min scored both goals in extra time to send South Korea into the final four at the third straight Asian Cup. The country is now two victories away from ending its 55-year drought at the continental tournament.

South Korea entered the match at Melbourne Rectangular Stadium banged-up. Midfielders Lee Chung-yong and Koo Ja-cheol had earlier been ruled out of the tournament with injuries, leaving Stielike with only 21 men.

After Thursday's victory, Stielike gave those remaining players kudos for their effort.

"We had problems in the first half, and I think it had to do with the pressure of playing in the must-win situation," Stielike said. "In the second half, we played with more poise and reduced our mistakes. We deserved to win based on the 30 minutes of extra time."

Stielike said South Korea has to fix technical issues if it were to go deeper in the tournament.

"We weren't sharp with our passes at all in the first half, but what's clear is that we're mentally strong," the coach added.

"Everyone came together trying to sacrifice for the team. We've lost two key offensive players in Koo Ja-cheol and Lee Chung-yong, and I have nothing but praise for our players for competing as one."

The coach noted that Son, who'd missed a game in the group stage because of a cold, still wasn't at 100 percent.

"I think he will play better in our next match," Stielike said.

"He lost the ball frequently, and it's not what you'd expect from a player who competes at the UEFA Champions League (for Bayer Leverkusen)."

The coach, however, gave Son a thumbs-up for great positioning on both of his goals and predicted that the football world still hasn't seen the best of the 22-year-old.

"I feel that Son needs to play with more composure at times," Stielike added. "In terms of speed and technique, he's beyond reproach. Yet he has to understand when to play with more patience depending on situations. I think Son will take this opportunity to be even better."

In Monday's semifinals, South Korea will meet the winner of the quarterfinals match between Iran and Iraq. Stielike said he hoped the two countries will go into extra time when they meet Friday.

"I'd like to see the players go out and have fun on the field (in the semis)," he added. "The important thing is we have to get over the mental hump. There will be a lot of pressure in the semifinals."

Though Son was the offensive star, defender Kwak Tae-hwi was named Player of the Match for helping keep Uzbekistan off the board. He later gave credit to his teammates.

"We faced some dangerous situations, but everyone on defense stood his ground," Kwak said. "That allowed (Son) to score the two goals. It took a lot of sacrifice from the whole team and everyone played a great match today." (Yonhap)