First meets second as Barcelona host Atletico Madrid on Saturday looking to tighten their grip on the La Liga title race.
The sides are level on 48 points at the top of the table, but Barca have a game in hand on Atletico and can take a huge step towards a fifth title in seven years with an eighth consecutive win in all competitions.
Indeed, Luis Enrique's men remain on course for a repeat of the treble of La Liga, Champions League and Copa del Rey they won last season after progressing to the semi-finals of the Cup with a come from behind 3-1 win over Athletic Bilbao in midweek.
Yet, the European champions have been far from their best in the past week as they were outplayed by Malaga and Bilbao in the first-half before being salvaged by individual moments of magic after the break.
"We are aware of the errors we need to correct," said Luis Suarez after taking his tally for the season already to 30 with the equaliser against Bilbao.
However, Atletico are also not in great form as they return to the scene where they won the title in the 2013/14 season. Diego Simeone's men were dumped out the Copa del Rey in midweek by Celta Vigo as they conceded three goals for the first time since Barca won by the same 3-2 scoreline at the same stage of the competition exactly a year ago.
Yet, it is at the other end of the field that Atletico have tended to have problems this season -- scoring just 30 goals in their 21 La Liga games so far.
"This defeat is not going to affect us on Saturday," said Atletico captain Gabi.
"We are used to having to fight for everything and on Saturday you will see the best Atletico Madrid."
The visitors are also likely to be confronted with a familiar face as Arda Turan takes on Atletico for the first time since making the switch to the Camp Nou following a four-year spell at the Vicente Calderon.
"I have had this match in mind for some time," the Turkish midfielder told Barca's website.
"You always have to respect the opponent and Atletico are no different in that aspect. Despite changing a lot of players, they have maintained the same style.
Both sides will be close to full strength with Barca set to recall Turan, Sergio Busquets and Andres Iniesta after they were rested in midweek, although Jordi Alba remains a doubt with a hamstring injury.
Atletico are without long-term injury absentee Tiago and Fernando Torres, whilst Angel Correa is suspended. Real Madrid trail the leaders by four points -- having also played a game more than Barca -- but have a golden opportunity to make ground on one or both of their title rivals when they host Espanyol on Sunday.
Zinedine Zidane suffered his first setback in charge of Los Blancos in a 1-1 draw at Real Betis last weekend. However, in contrast to their away form, Real have been lethal at home in recent months, scoring 35 goals in their last six games at the Santiago Bernabeu.
They also hit Espanyol for six when the sides met at Cornella-El Prat earlier in the season with Cristiano Ronaldo scoring five. Gareth Bale is expected to miss out once again for Real despite stepping up his recovery from a calf strain, so James Rodriguez is expected to deputise for the Welshman.
Elsewhere, Gary Neville has a great chance to finally record his first league win as Valencia boss at the eighth attempt when Los Che host a Sporting Gijon side that have lost their last eight away games.
Fixtures (all times GMT)
Saturday: Barcelona v Atletico Madrid (1500), Eibar v Malaga, Getafe v Athletic Bilbao (1715), Villarreal v Granada (1930), Real Sociedad v Real Betis (2105);
Sunday: Sevilla v Levante (1100), Valencia v Sporting Gijon (1500), Las Palmas v Celta Vigo (1715), Real Madrid v Espanyol (1930)
Monday: Deportivo la Coruna v Rayo Vallecano (1930).
