Barcelona ended their five-match winless run with a comfortable victory over Athletic Bilbao and stretched their lead to six points at the top of the Primera Liga.
The win was made sweeter by the fact title rivals Real Madrid could only draw at home to city rivals Atletico.
Sergio Busquets gave the Catalans the lead after 17 minutes and Lionel Messi added a second from the penalty spot on the half-hour mark to seal a first win in a month for the league leaders.
Barcelona had seen their 12-point advantage over Real Madrid shrink to just four following a draw and two defeats in their previous three league matches.
But Guardiola's side did progress to the final of the Copa del Rey on Wednesday following a 1-1 draw at Mallorca in the second leg of the teams' semi-final tie.
The Catalans will face Athletic in the showpiece at Valencia's Mestalla stadium on May 13, and today against the same opposition they soon took control.
Andres Iniesta saw an effort deflected behind for a corner after just four minutes and Rafael Marquez then blasted a long-range shot over the bar as Guardiola's side sought an early advantage.
Athletic almost took the lead after 16 minutes, though, when Fran Yeste found himself one-on-one with Victor Valdes, but slid his shot agonizingly wide of the target.
The Basque forward was left to rue his miss a minute later as Barcelona took the lead, when Busquets climbed above his marker to head past Gorka Iraizoz from Xavi's free-kick.
Following the team's poor recent run, the relief was tangible around the Nou Camp.
And there was even more cheer to come for the Barca faithful as the locals went two up after half an hour.
The hapless Carlos Gurpegi - who had been outjumped by Busquets as Barca took the lead - fouled Iniesta and Messi stepped up to coolly fire home from the spot.
This was not classic Barcelona, but the Catalans almost went three up six minutes before half-time, when Samuel Eto'o was just off target with a stunning overhead kick.
Guardiola's side went even closer to a third goal just after the break, when Iniesta crashed a shot against the post.
Iraizoz then produced a fine save to stop an Eto'o header and Gerard Pique saw his effort cleared off the line as Barca pushed for a third goal.
Eto'o struck the woodwork from close-range and Thierry Henry also missed two great chances to put the game out of sight in the closing stages.
But two goals was always going to be enough against an Athletic side which looked a pale imitation of the team that thrashed Sevilla 3-0 to advance to the final of the Copa del Rey on Wednesday.
With Madrid only managing a draw at home to Atletico in the capital derby match played at the same time, Barca are again moving away from their nearest rivals at the top of the table after 26 rounds of the championship.
Athletic, meanwhile, stay in 11th for now, but could drop two places on Sunday.
