From left to right: Bayern Munich head coach Pep Guardiola, Barcelona coach Luis Enrique, Chelsea manager Jose Mourinho, and Real Madrid coach Carlo Ancelotti. [Photos/Agencies]

MANCHESTER, England?- With nine different winners in the last 11 years, no one could ever accuse the Champions League of being predictable.

It does appear, however, that an established "Big 4" has been created in Europe's premier club competition?- and this year's group stage backs up the theory.

Barcelona, Chelsea, Bayern Munich and Real Madrid, the last four winners of European soccer's top prize, were the top teams in group play, which finished Wednesday. In each of the last three seasons, at least three of that quartet has reached the semifinals of the Champions League. Madrid and Barcelona did so in 2011, too.

So, heading into the knockout stage that kicks off in February, it would be a big surprise if this season's champion didn't come from this small pool of juggernauts?- teams who currently are playing football at another level to the rest.

"Everybody's there, so the Champions League starts now," Chelsea manager Jose Mourinho said of a last-16 lineup that contains 11 of the teams who advanced in the 2013-14 season.

No club has ever successfully defended the Champions League title since the competition's inception in 1992. Could Madrid be about to end that jinx?

At top of the Spanish league, a team boasting the attacking talents of Cristiano Ronaldo, Gareth Bale, James Rodriguez and Karim Benzema was the only one to pick up a maximum 18 points in the group stage. Madrid has won its last 19 games in all competitions and Ronaldo, the reigning world player of the year, has already reached 30 goals for the season.

"I know I've got an extraordinary team," Madrid coach Carlo Ancelotti said after Tuesday's 4-0 win over Ludogorets Razgrad. "I don't tire from saying this."

Any side that contains Lionel Messi will always have a great chance, and Barcelona will be expected to reach the semifinals after missing out last season. Barcelona's defense remains a concern?- although it has only conceded seven goals in 14 games in the Spanish league?- but Wednesday's 3-1 win over Paris Saint-Germain at Camp Nou gave a taster of what to expect from its expensively assembled, all-star attack.

Messi?- with his record-extending 75th Champions League goal?- was on the score sheet along with Neymar and Luis Suarez. The trio is six weeks into its new partnership and when the last 16 comes around it could be unstoppable.

"We know that together we can go places," Suarez said Wednesday after Barcelona sealed first place in its group for the eighth straight season.

Bayern's only defeat in a tough-looking Group E came at Manchester City after playing more than 70 minutes with 10 men and conceding twice in the last five minutes to lose 3-2. The German champions have few weaknesses in their team, with their attack looking even stronger with the addition of Robert Lewandowski, and have a coach in Pep Guardiola who has gone all the way before in the Champions League, with Barcelona in 2009 and '11.

Chelsea, meanwhile, has found a cure to its attacking frailties of last season with the signing of Spain striker Diego Costa and was the top-scoring team in the group stage, with 17 goals in six games. Traditionally strong in defense, Eden Hazard is developing into one of the world's best wingers and Cesc Fabregas has brought more creativity into the team's midfield.

"Last season, for sure we were not one of the top four and we played in the Champions League semifinals," Mourinho said. "Let's see what we can do this season."

Mourinho said there will be some "sharks in the ocean" in Monday's draw for the last 16. He was probably referring to Man City, PSG and Italian champion Juventus, who appear to be the strongest teams among the runners-up.

Europe has been waiting for big-spending City, English champions twice in the last three seasons, to find its feet in the Champions League. And a 2-0 win at Roma on Wednesday that sealed advancement was viewed by some as a coming-of-age result, secured without arguably its four key players in Sergio Aguero, Yaya Toure, David Silva and Vincent Kompany.

City's flaws and tactical limitations in Europe were exposed previously in the group stage, though, and it is unlikely to infiltrate the four favorites.