The K-League title race will go down to the final day after Ulsan missed the chance to secure the crown as they lost 2-1 to Busan I'Park.
A second-half double from Lee Jung-Ho ended Ulsan's run of six consecutive wins as Busan came from a goal down to secure a memorable victory.
Victory for Kim Ho-Gon's side would have secured their first title since 2005 but instead they face a title-deciding match against Pohang Steelers on Sunday.
Pohang moved to within two points of the leaders with a 3-1 victory over Seoul earlier on Wednesday, a 13th minute strike from Kim Seung-Dae and a double from No Byung-Jun enough to secure a 20th win of the season and set up a thrilling campaign finale.
Elsewhere in the Championship Round, Suwon Bluewings ended a run of five consecutive defeats as they beat Jeonbuk Motors 1-0.
Santos' 90th minute strike secured the three points for Seo Jung-Won's side, and leaves Jeonbuk and Seoul with a straight fight for the third and final AFC Champions League spot when they meet on Sunday.
In the Relegation Round, Daejeon Citizen's valiant attempt to rescue their season ended in vain as a 1-1 draw with Gyeongnam saw them relegated from the top flight.
Han Kyung-In had opened the scoring for Daejeon in the 77th minute as they looked on course to record a fifth straight win, however an 82nd-minute equaliser from Kang Jong-Kuk sent them down.
The point was enough to secure Gyeongnam's place in the top tier, but Gangwon missed the chance to secure their own safety, drawing 2-2 with second-bottom Daegu.
Choi Seung-In's late double rescued Gangwon from two goals behind, and they will now need a positive result against Jeju United on the final day, although defeat for Daegu at home to Gyeongnam will secure their place in the relegation play-off - in which they will have another chance to preserve their top-flight status against Sangju Sangmu.
Seongnam ended their campaign with a 1-0 victory over Chunnam Dragons, Kim Dong-Sub's strike nine minutes from time was enough to secure all three points for the visitors.
|Coach: Seong-Hyo Yoon|
for Dong-Min Yoon 80'
for Sung-Chan Jeon 85'
for Ji-Ho Han 90'
|Tottenham deal for Son not complete, say Leverkusen|
|Tuchel thrilled with aggressive Dortmund display|
|Midtjylland 1 Southampton 0 (2-1 agg): Premier League side crash out|
|Borussia Dortmund 7 Odd 2 (11-5 agg): Reus hat-trick highlights hammering|
|Cudicini tips Mourinho to avoid Porto upset|
|Anything is possible with Neymar´s future - Belletti|
|Burnley bring in Barton|
|Bayern Munich v Bayer Leverkusen: Vidal putting friendships on hold|
|De Bruyne edges closer to City move after further Wolfsburg talks|
|Real Madrid v Real Betis: Benzema back as Real look to hit the goal trail|
|Barcelona v Malaga: Rosales hopes for another upset|
|West Brom hit out at Tottenham´s Berahino pursuit|
|Stoke City v West Brom: Pulis set for Britannia return|
|Tottenham v Everton: Pochettino´s men eye first win|
|Everton reject Stones´ transfer request|
|Messi named UEFA Player of the Year|
|Pocehttino quiet on Berahino bids|
|Real Madrid to meet PSG in Champions League, Barca drawn with Leverkusen|
|Bournemouth v Leicester City: Howe eager to entertain|
|Ranieri coy on Gray link|
|Newcastle United v Arsenal: Wenger hopes for sharper shooting|
|PSG snap up Kurzawa from Monaco|
|Aston Villa v Sunderland: Sinclair aims to replicate cup form|
|Grabban a silly boy - Neil|
|Chelsea v Crystal Palace: Pardew braced to face stronger champions|
|Manchester City v Watford: Flores heads to Etihad with confidence|
|Marseille loan Real Madrid youngster Lucas Silva|
|Howe surprised by Harte´s retirement|
|Liverpool v West Ham: History counts for nothing, says Bilic|
|Bolasie set for Palace comeback|
|De Bruyne to City not a done deal - Allofs|
|Sevilla complete Llorente swoop|
|Wenger supports video technology|
|Milan v Empoli: Zapata sets sights on ´must-win´ fixture|
|Watford boss Flores ´not happy´ with transfer situation|
|Balotelli: I am no longer a kid|
|Bilic has no issue with Valencia|
|Arsenal ´not close´ to any late deals|
|Balotelli finalises return to Milan on loan|
|West Ham confirm Nolan departure|
|Thiago signs new Bayern deal|
|Schmidt saddened as Son nears exit|
|CONCACAF Champions League Review: Sounders lose in Honduras|
|Van Gaal considered early Herrera substitution|
|MLS Review: Fire stun Red Bulls|
|Carroll nears West Ham return|
|Rodriguez hoping for England recall|
|Leverkusen can challenge best - Schmidt|
|Ozil defends United recruit Schweinsteiger|
|Sporting ´better over two legs´ - Jesus|
|Stoilov revels in historic Astana triumph|
|Pioli: Lazio not ready for Champions League|
|UEFA Champions League Review: Rooney nets treble and Astana make history|
|Everton to reject Stones´ transfer request - Martinez|
|Barnsley 3 Everton 5 (aet): Delightful Deulofeu spares blushes for Martinez´s men|
|Van Gaal lauds Rooney character|
|Rooney delighted to be back in the goals|
|Club Brugge 0 Manchester United 4 (1-7 agg): Rooney ends goal drought with hat-trick|
|Juve striker Llorente undergoing Sevilla medical|
|Blanc confirms imminent Kurzawa switch to PSG|
|AFC Champions League Review: Lima gives Al Ahli the edge, Jeonbuk Motors and Gamba Osaka draw|
|Wanyama out of Euro tie with stomach infection|
|Digne joins Roma on loan from PSG|
|Monaco agree deal for Real´s Coentrao|
|Wolves reject third Norwich bid for Afobe|
|Valencia clarifies West Ham criticism of injury treatment|
|O´Neill hands duo Northern Ireland recalls|
|Illarramendi makes Sociedad return|
|Arsenal a player away from dominance - NBA star Deng|
|Godin ´always wanted´ Atletico stay|
|Schalke reject Roma´s Kolasinac bid|
|Injured Allen omitted from Wales squad|
|Bellerin ready for Debuchy battle|
|Valencia lashes out at West Ham treatment|
|Van Dijk hints at Celtic exit|
|Everton legend Gray resigned to Stones exit|
|Negredo: Suffering is in the past|
|Commons and Gordon reject Deila critcism after Celtic defeat|
|Neil remains defiant on Bournemouth target Grabban|
|Happy Milner optimistic about Liverpool chances|
|CONCACAF Champions League Review: DC United, Saprissa preserve perfect records|
|Tomkins eyes West Ham recall|
|Di Maria, Pastore out of Argentina squad|
|Schmidt unfazed by Lazio injuries|
|Pique hits back at Barca critics|
|Hurt Traore a ´marked man´ - Sherwood|
|Wolves reject second bid for Norwich target Afobe|
|Pardew fears ´long term´ Jedinak injury|
|Hughes thrilled with Bojan return|
|Maccabi´s Europe feat ´the high of highs´ for Ben Haim|
|McClaren expecting big things from Thauvin|
|Lucescu calls for Shakhtar improvement in group stage|
|Watford will learn from loss - Flores|
|Nuno revels in Valencia´s Champions League qualification|
|Advocaat unhappy despite win|
|League Cup Review: Preston claim Watford scalp, Luton lose shoot-out to Stoke|
|UEFA Champions League Review: Valencia make history for Spain, Celtic dumped out|