Often enough in the past, progress in the UEFA Champions League has made a team vulnerable in their next domestic fixture, but all four semi-finalists in Europe's elite club competition chalked up valuable points at the weekend. Chelsea maintained their challenge for a place in the Premier League top four, and Bayern Munich continue to snap at the heels of Bundesliga leaders Dortmund. In La Liga, Barcelona made up two points on Real Madrid, as the men from the capital were the only one of the four not to win.

FIFA.com examines five interesting aspects of the weekend action in Europe’s major leagues, and also casts an eye over events elsewhere, including Scottish title celebrations, and a good weekend for the reigning champions in Portugal.

One match
Arsenal-Manchester City, Matchday 32 in the Premier League
Is Manchester City's title challenge over? Roberto Mancini's men fell 1-0 away to Arsenal, their third Premier League match without a win. The situation in the table, where Manchester United are now eight points clear, strongly suggests that the side in light blue have run out of steam just as their experienced rivals in red grind out victory after victory.

At the Emirates Stadium, the home side were in charge for long spells, but the winning goal came just as the visitors sensed they might come away with a draw - Mikel Arteta firing home a stunning winner for the Gunners three minutes from time. Rubbing salt into City wounds, Mario Balotelli contrived to get himself sent off for a second bookable offence.

Arsenal are out of the title race, but cemented their grip on third spot and a direct Champions League qualifying place ahead of north London rivals Tottenham Hotspur.

Two teams
After a four-year gap, Glasgow giants Celtic have recovered the Scottish championship. Arch-rivals Rangers were 15 points clear at an early stage of the season, but a points deduction for financial irregularities at the club and a run of 17 wins on the trot for the Hoops turned the situation on its head. The Bhoys sealed it once and for all at the weekend with a 6-0 thrashing of Kilmarnock to claim the title for the 43rd time. Manager Neil Lennon, a five-time champion with Celtic as a player, described the triumph as “the greatest moment in my professional life".

In the 32nd round of La Liga fixtures, suburban Madrid outfit Rayo Vallecano ran up a historic victory. The team coached by Jose Ramon Sandoval rattled up their biggest-ever victory in the Spanish top flight as they handed Osasuna a 6-0 hiding. “I think we could have won by more," an effusive Sandoval said afterwards. "We hit the goal frame a couple of times, and we missed a number of chances. We were unbelievable."

Three players
Substitute Amauri delivered a knockout blow to Italian leaders AC Milan with the winning goal for Fiorentina a minute from time. The Brazilian, who also holds an Italian passport, left Juventus after seeing his prospects dwindle under Antonio Conte, but his goal not only handed his current team some breathing space in the relegation battle, it also allowed his former club to move to the top of the Serie A standings.

Since arriving in the Premier League, Papiss Demba Cisse has been scoring almost at will. Before Christmas, much of the talk at Newcastle United was about fellow striker Demba Ba, another Senegalese international. However, since joining the Magpies from Freiburg in the January sales, Cisse has been just as sensational, scoring his third brace on the bounce this weekend against Swansea to take his tally to nine goals in just eight matches.

Clint Dempsey passed not one but two career milestones at the weekend. The USA midfielder is enjoying his most prolific season to date, and also clocked up his 250th league appearance. Fulham stalwart Dempsey celebrated the occasion with a double strike against struggling Bolton Wanderers and is now on 15 goals for the season.

Four stats
- The Belgian programme featured a ten-goal thriller as Cercle Brugge beat Louvain 6-4, in one of those matches where practically every shot went in. It was not even that either keeper had an off day, but rather that the strikers were on sparkling form.

19 - Since a 1-0 home victory over Freiburg on Matchday 10 in the Bundesliga, Kaiserslautern have gone 19 games without a win. A recent change of coach failed to reverse the Red Devils’ fortunes, as Marco Kurz’ successor Krassimir Balakov remains winless in the German top-flight.

24 - Mario Gomez required just 24 seconds of play for the first of his two goals for Bayern against Augsburg. The opening strike at the Allianz Arena was the fastest of the current Bundesliga season. At the moment Gomez was handing Munich the lead, direct title rivals Borussia Dortmund were still waiting to kick off away to Wolfsburg.

161 - Barcelona's 4-1 victory over Zaragoza saw the Catalans write a new chapter in Spanish footballing history. The national record for the highest number of goals scored in a single season previously stood at 158, but Barça are already on 161 from 54 competitive fixtures this term.

Five memorable moments
Credit where it's due: Nolan Roux finished top scorer for Brest in 2010/11, before taking his goalscoring instincts to Lille for the new season. The striker, who has a combined total of 11 goals and assists so far, returned to his former stamping ground at the weekend, where he was given a prodigal son’s warm reception by the home faithful. However, it ended unhappily for Roux as Lille fell 3-1.

Bountiful braces: Matchday 29 in the Bundesliga was a good day for the strikers, with a string of stars chalking up doubles. Gomez, Robert Lewandowski, Raul and Vedad Ibisevic all grabbed a brace apiece, although Gomez is now out on his own at the top of the scoring charts, as chief rival Klaas Jan Huntelaar of Schalke managed only a single strike at the weekend.

Getting the priorities right: The San Siro crowd rose as one on 83 minutes to hail the return of Antonio Cassano, making an emotional comeback five months after urgent heart surgery. AC Milan ultimately fell to a last-gasp defeat against Fiorentina and were knocked off the top of the table by Juventus, but that pales into insignificance compared to the heart-warming comeback on the day.

Curse of the Europa League: Atletico Madrid have marched into the UEFA Europa League semi-finals, but their domestic league form leaves much to be desired. Atletico fell 2-0 to Levante and have slipped out of the European qualifying places in La Liga. By contrast, Levante are the undisputed surprise package of the Spanish season and retain hopes of a shot at Champions League football, as the victory over Atletico sends them fourth, at least overnight.

Then there were two: In the clash between the leaders and the side lying third in Portugal, Porto all but shook off fellow contenders Braga with a 1-0 victory. Braga had previously won 13 on the bounce, but this defeat against Porto was their second in a row and they now lie five points off the champions with only four games to play. The race in Portugal is now effectively a two-horse affair, although Benfica urgently require victory over Sporting in Monday's Lisbon derby to keep alive their title hopes