Barcelona and tournament specialists Sevilla are hoping to secure spots in the quarter-finals of the Europa League this week with three Spanish teams still in a competition dominated by La Liga clubs in recent years.
A rejuvenated Barca head to Istanbul for the second leg of their last-16 tie against Galatasaray on a 10-game unbeaten run that has propelled them back up to third in La Liga and seen them emerge as one of the favourites to win the Europa League.
"The fans are enjoying themselves when they come to the stadium, and so are we out on the pitch," said Gerard Pique, who played his 600th game for Barcelona in Sunday's 4-0 defeat of Osasuna.
"The results are coming back and we hope to keep this going through to the end of the season," the veteran centre-back told the club's website.
However, Xavi Hernandez's side were held 0-0 at home by a struggling Galatasaray in the first leg of their Europa League tie last week so still have work to do to reach the quarter-finals.
Meanwhile Sevilla are in London to play West Ham United with a 1-0 lead from the first leg given to them by Munir El Haddadi's goal.
Six draws in their last eight league games have effectively ended their domestic title hopes, leaving Julen Lopetegui's charges 10 points adrift of leaders Real Madrid.
But they remain on course for more success in the Europa League as they look to win a trophy they have already lifted a record six times, all since 2006.
Sevilla also have the incentive of trying to reach a final that will be played in their own stadium, the Ramon Sanchez Pizjuan, on May 18.
They left the injured Marcos Acuna out of their squad for the journey to the United Kingdom to face a West Ham side who see the Europa League as their best chance of a first major trophy in over four decades.
"We need to score and I hope, on Thursday, in front of a full stadium, we show our quality and make the most of the opportunity," said Hammers midfielder Tomas Soucek.
West Ham are the sole English representative still in the Europa League, while Manuel Pellegrini's Real Betis are the third Spanish side as they head to Germany to play Eintracht Frankfurt bidding to overturn a 2-1 deficit.
Spanish clubs have won seven of the last 10 editions of the Europa League,including last year when Villarreal beat Manchester United on penalties in the final.
Rangers are primed to advance to the last eight after winning 3-0 at home to Red Star Belgrade in last week's first leg, while Braga, Atalanta and Lyon will also defend first-leg leads.
RB Leipzig earned a bye to the quarter-finals after last-16 opponents Spartak Moscow fell victim to the ban on Russian clubs.
In the Europa Conference League, Leicester City are well placed to reach the last eight as they defend a 2-0 first-leg lead on their trip to France to play Rennes.
Marseille, Roma and Feyenoord are among the other sides defending first-leg advantages.