Lanus defeated 10-man Arsenal 2-0 on Monday, to climb above their opponents into fourth spot in the Argentina Primera Division.
Arsenal's trip to the Estadio Ciudad de Lanus was looking like a fruitful one with 10 minutes to play, as they had their eyes on a valuable away point to boost their title chances.
However, the effect of Arsenal defender Hugo Nervo's dismissal on 64 minutes was felt late on, as Nicolas Pasquini and Santiago Silva both found the back of the net to send Lanus within four points of league leaders Newell's Old Boys.
Pasquini's 83rd-minute goal was followed by Silva's on-target shot three minutes later.
Lanus's fourth straight win sees them to 25 points, with Arsenal fifth only on goal difference.
Earlier in the weekend, top two sides Newell's and San Lorenzo played out a 1-1 draw to blow open the race for the Torneo Inicial title - with four matches to play in the season.
The hosts at the Estadio Marcelo Alberto Bielsa in Rosario led on 25 minutes when David Trezeguet struck, only for Ignacio Piatti to equalise for San Lorenzo five minutes later to keep the league leaders within reach.
San Lorenzo are two points behind Newell's in second, while Boca Juniors are third - level on 27 points with San Lorenzo - after a stunning late show to beat Tigre 2-1.
Tigre had their eyes on all three points from their trip to the Estadio Alberto Jacinto Armando in Buenos Aires, after a Claudio Perez own goal in the 18th minute gifted them the lead.
However, the visitors lost attacker Matias Perez Garcia to a red card eight minutes after the interval, and despite keeping out Boca for the most part, the dam wall broke in the final stages.
Leandro Paredes equalised on 85 minutes, before Daniel Diaz struck in the second minute of injury time to give Boca hope of titles in consecutive years after their Apertura success in 2012.
Atletico Rafaela chalked up their first league win in four matches, with a 3-1 result at home to Godoy Cruz.
A Diego Vera brace consolidated Diego Ferreira's opener for Rafaela, with the win taking them to 24 points.
Estudiantes are one point behind fifth-placed Rafaela in sixth, after a 1-1 draw at home to Rosario Central (ninth).
Rosario led on 51 minutes via a Paulo Ferrari goal but the points were split after defender Alejandro Donatti got the final touch into his own net seven minutes later.
Argentinos Juniors continued their stellar form, making it three wins from their past four with a 1-0 win away at Racing Club.
Hernan Boyero was the hero for Juniors, as they moved to 23 points and eighth spot on the table.
In other results, Quilmes had a 1-0 win away to Olimpo, All Boys were too good for Gimnasia La Plata 2-1, Belgrano's Cesar Pereyra scored both goals in his side's 2-0 win over Colon, while River Plate's trip to Velez Sarsfield ended 0-0.
|14||J. Pereyra Díaz|
|Coach: Guillermo Barros Schelotto|
for J. Pereyra Díaz 63'
for F. Barrientos 82'
for D. González 90'
|Deschamps calls up Martial, leaves out Sakho|
|´The only thing they can is long balls´ - Midtjylland´s skipper slams Southampton|
|UEFA Europa League Review: Reus leads Dortmund rout, AZ complete late comeback|
|Messi should win Ballon d´Or - Bartomeu|
|Koeman rues refereeing decisions after Europa League defeat|
|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|