Racing left it late to maintain its Uruguayan Primera Division lead with a 1-0 win over Tacuarembo.
Racing remains one point in front of Nacional atop the Apertura table but was made to work for its latest triumph.
Tacuarembo entered the match having lost three of its last four but was resolute in defence, frustrating its more-fancied opponent.
And Racing looked like failing to score for the first time since March until Franco Sosa's unfortunate 90th-minute own goal.
Nacional won far more easily – Carlos De Pena's first-half double gave it a 2-0 win at Atenas.
Rentistas is three points behind Racing after a comfortable 3-0 triumph at Danubio.
Ignacio Ithurralde gave Rentistas the lead in the 44th minute and further strikes from Hugo Soria and Federico Laens sealed the triumph.
Penarol lost further ground on Racing despite maintaining its unbeaten record this season, a third successive draw leaving it four points off the pace.
Penarol, which could reach the Copa Sudamericana's last 16 with victory at Colombia's Deportivo Cali in midweek, had to come from behind to win a 1-1 draw at El Tanque Sisley.
Juan Manuel Olivera scored the equaliser with seven minutes to play.
At the other end of the table, rock-bottom Cerro ended a run of five losses with a goalless draw at Sud America.
Cerro is still two points adrift of Atenas.
Elsewhere, Defensor Sporting extended its unbeaten run to four with a 2-0 win over Juventud.
River Plate ended a run of two losses with a 3-1 success against Fenix, while Rampla Juniors won 1-0 at Wanderers.