The 2021-22 season has kicked off on an explosive note, with many teams across Europe's top five leagues looking to make huge statements.As always, all eyes have been on the top dogs to step up and prove why they're considered the favourites to win the major competitions. There are also a few teams who entered the season without much attention, but have impressed with their performances.These teams have upset the odds by beating the so-called favourites, and have bagged key victories across domestic and continental competitions. In other words, these teams have exceeded expectations this season. On that note, here's a look at the top five such teams:#5 West Ham UnitedThe Hammers are just three points below the top spot.West Ham have caught the attention of many as they continue wrestling with England's elite teams this season. The Hammers knocked Manchester United out of the Carabao Cup with a 1-0 victory last week.B/R Football@brfootballWest Ham knock Manchester United out of the Carabao Cup 😬9:44 PM · Sep 22, 2021329642867West Ham knock Manchester United out of the Carabao Cup 😬 https://t.co/TzNXXjsOVCThey also had a decent start to their Europa League campaign, beating Dinamo Zagreb 2-0 away from home. So far, they've recorded three victories, two draws and one defeat in their six Premier League games this season.They currently rank seventh in the table with 11 points, just three points behind table-toppers Liverpool. David Moyes' men are playing some incredible football, and have risen up to the challenge, especially against the top teams.Their only loss of the season so far came against Manchester United in the Premier League, where the latter scored an 89th-minute winner.#4 Brighton & Hove AlbionBrighton occupy the sixth spot in the Premier League table.Like West Ham, Brighton & Hove Albion have also caught many by surprise with their brilliant performances in the Premier League this season. The Seagulls will move to the top of the table if they claim victory against Crystal Palace this evening.Premier League@premierleagueTonight, Brighton have the chance to go top of the #PL 🔵07:31 AM · Sep 27, 2021131411067Tonight, Brighton have the chance to go top of the #PL 🔵 https://t.co/PYJT7BrZv3They are currently fifth in the table with 12 points from five games, just two points adrift of table leaders Liverpool.Brighton have been the second-best defensive team in the English top flight so far this term. They have conceded just four goals since the league restarted. Only Manchester City have a better defensive record with just one goal conceded.With four victories and one defeat from five games, it is impossible to deny that the Seagulls are doing pretty well this season. If they continue with the same level of performance, they might surprise many.