Here are some impressive results of professional defenders:
Joo, Saehuyk (KOR)
2001 Runner-up Japan Open
2003 Runner-up World Championships
2006 Winner Korea Open
2010 Runner-up Korea Open
2011 3rd place Mens World Cup
2012 Runner-up Hungarian Open
2012 Runner-up Brazil Open
2016 Winner Croatian Open
...and many more semifinals over 2 decades!!!
Hou, Yingchao (CHN)
2000 Winner National Championships (China)
2001 Winner Finland Open
2006 Runner-up German Open
2006 Winner Russia Open
Ding, Song
1994 Winner Swedish Open
1995 Semifinalist World Championships
1995 Winner Japan Open
1996 Winner Japan Open
1997 Winner Australian Open
Chen, Xinhua (CHN,ENG):
1985 Winner Mens World Cup
other results:
1981 Winner National Championships (China)
1981 Winner Finland Open
1990 Runner-up England Open
1992 Winner Italy Open
1993 Runner-up Swedish Open
Li, Gun Sang (PRK)
1987 Semifinal Hungarian Open
1988 Runner-up French Open
1989 Winner Swedish Open
1990 Winner World-Allstars-Circuit (Nagaoka)
1990 Winner World-Allstars-Circuit (Hamamatsu)
1993 Winner Asian Cup
Wang, Hao (YoB 1966) (CHN)
1987 Winner Finland Open
Shibutani, Hiroshi (JPN)
1991 Runner-up World-Allstars-Circuit (Tokyo)
1997 Semifinal Swedish Open
Matsushita, Koji (JPN)
1995 Runner-up World-Allstars-Circuit (Tadotsu)
1996 Semifinal Japan Open
Matsushita/Shibutani also got some great result in mens doubles ...