|Guardiola's contract extension has been a boost to the club [AFP]
Spanish champions Barcelona crushed Real Valladolid 3-0 away to move eight points clear at the top of Spain's Primera Division on Saturday, reaching the mid-point of the season unbeaten for the first time.
The result opened up their advantage over rivals Real Madrid and rounded off a positive week for the champions, in which coach Pep Guardiola ended speculation over his future by agreeing to a one-year contract extension.
Xavi Hernandez and Daniel Alves scored for the defending champions in the first half and Lionel Messi added the third as Barcelona comfortably won their third game in a row - having outscored opponents 12-0 during that span.
Alves was behind many of Barcelona's best attacks down the right flank and sent a perfect cross into the area that found the unmarked Xavi, who volleyed in the opening goal in the 20th minute.
Two minutes later, Alves was played clear down the right and curled a right-footed shot from outside the area over goalkeeper Justo Villar inside the far post. Messi then scored his league-leading 15th goal in the 56th after a pass from Zlatan Ibrahimovic.
Barcelona have won 15 games and drawn four for 49 points. Madrid have 41, Valencia are on 38 while Sevilla joined Mallorca with 33 points following a 1-0 win over Almeria earlier on Saturday.
Madrid can narrow the gap back to five points on Sunday when they play Malaga.
Athletic, Espanyol, Madrid and Real Sociedad also finished the first half of the season unbeaten.
The result was Barcelona's second highest points total after 19 games - one less than the Spanish champions had at the same point last year.
The defending champions faced early pressure from the hosts.
Barcelona then started creating chances, with Messi's hard shot in the 11th minute saved by Villar.
Barcelona goalkeeper Victor Valdes saved from Diego Castro in the 18th and kept out Borja Fernandez's hard free kick in the 43rd.
Messi nearly scored again in the 64th but fired wide, and Villar then saved from Ibrahimovic.
Meanwhile, a lucky goal on a water-logged pitch was enough for Sevilla to end a four-game league losing streak.
Defender Santiago Acasiete attempted a pass to goalkeeper Diego Alves deep inside the Almeria area in the ninth minute but the ball slowed to a halt on the soaked field, allowing Renato to pounce on it and centre to Negredo for an easy tap into the empty goal.
Sevilla eliminated Barcelona in the Copa del Rey this month but were on their worst streak in more than a decade in the league.
Sevilla were without striker Frederic Kanoute but played with more tenacity and verve than in recent weeks. Negredo was behind most of the best chances, including a low shot that rolled wide of the post in the 34th.
Almeria had several chances to equalise but struggled with poor finishing, as goalkeeper Andres Palop saved Henok Goitom's effort in the 19th and Fernando Soriano's in the 69th.
"We were efficient'' Negredo said.
"They also had occasions but they just didn't take advantage.''