Sun showed great character by not letting this huge disappointment derail him and worked very hard to establish himself at his club.

Sun made his debut for Crystal Palace in a 3–0 loss against Bury in the first leg of a 1998–99 Football League Cup match.

In October 2002, Sun became the first East Asian footballer to score in the Premier League when he headed home the first goal in a 2–0 win over Birmingham City.

After recuperating and following a strict physical regimen devised by his father, Sun re-installed his place as a regular in the club's starting lineup.

The Football Association charged him for his behavior after receiving a red card even with his past good disciplinary record and handed him an additional one-match ban.

Having played regularly until November he succumbed to an injury and subsequently failed to force his way back into the first team and made only a handful of appearances in the FA Cup in the second half of the season.

[7] In July 2009, Sun was loaned to Sheffield United's satellite team Chengdu Blades in the Chinese Super League, hoping to make an impact.

At the 2002 FIFA World Cup in a group stage match against Costa Rica, Sun picked up an ankle injury after a tackle from behind by Mauricio Solís after just 17 minutes.

Unable to play, Sun was replaced after 25 minutes and sat out the rest of the group stage, while Solís was only shown a yellow card.

On 7 June 2008, during a 2010 FIFA World Cup qualification match against Qatar, Sun was shown a straight red card for dissent while he was warming up as a substitute on the bench.