Took 1st?
SEAM 2013 is AFAIK the only one. However you can’t just look at “took 1st” and ignore everything else. Check out how often Adon has appeared in top 8 at majors:
Evo 2012 - Gamerbee was in grand finals took 2nd
Dreamhack 2013 - Gamerbee took 2nd
Shadowloo Showdown - Gamerbee took 2nd
Taiwan SF 25th tournament (not the Capcom Cup qualifier. The one big one) - Gamerbee took 2nd
WGC 2013 - Gamerbee took 3rd
ECT4 - Gamerbee took 3rd
VXG 2013 - Gamerbee took 3rd
Gamerbee other top 8 majors placements in AE2012:
Evo2013
CEO2012
Shadowloo Showdown 2012
SF 25th Anniversary
Winterbrawl 8
Ramen Addict - Placed top 8 at CEO2013 and Final Round 15 (2012)
Ettelman (Swedish player) - 4th at Dreamhack Summer 2013 (that is the one where Popi beat Infiltration)
That is only going by the stuff listed on here: http://rank.shoryuken.com/rankings/index?pchar=Adon
There may be plenty of other examples not catalogued.