The South Korean star was just moving up from Hamburg’s reserve side into the German outfit’s first team when they hosted the Blues in a pre-season friendly in August, 2010.
A little-known 18-year-old at the time, Sonny duly introduced himself by stepping off the bench and bagging Hamburg’s 87th-minute winner as they scalped the Londoners 2-1 at their Volksparkstadion base.
Now, five years down the line and with five successful years in the Bundesliga under his belt prior to joining us this summer, the crafty attacker meets Chelsea once more with Premier League points at stake as we face the Blues in a Sunday showdown at White Hart Lane.
Always eager to hit the target, Sonny hopes his landmark goal from 2010 can inspire him to help us to victory this weekend.
“I remember scoring against Chelsea,” he said. “It was my first goal in the stadium for Hamburg, I was 18 and I scored the winning goal for 2-1 so it was a great time.
“Before that most people didn’t know me but after I scored against Chelsea all the fans and the Korean papers were all talking about ‘Sonny, Sonny, Sonny’ so it was amazing for me.
“It’s always very important to play and score and I hope that this time I can do the same. We will see!”
As for the idea of facing another big London derby following our 1-1 draw at Arsenal and 4-1 triumph over West Ham this month, Sonny has highlighted the need for teamwork and a positive attitude if we’re to get the better of the Blues.
“They are a very big team with good players,” he warned. “Before the season everyone said that Chelsea would win the Premier League. They are a very good team but if we play like we did against West Ham with all players with the same mind, we can win.
“It’s very important to have a good mentality because it’s not a normal game. It’s a London derby, it’s important for the fans and for us. We are young, strong mentally and every game the demand is to try to win.
“In the dressing room and in the squad there is a positive mentality – for me it’s very important to play with that mentality. I hope we win – we will try our best for the fans and for us.”