Arsenal faced many difficulties as predicted when traveling to Sunderland's The Light stadium. The knot of the match came in the situation where the away team conceded a penalty in the context that the score was still 0-0. After the match, Mikel Arteta criticized it as an "unacceptable" decision because if Sunderland scored in that situation, Arsenal would face the risk of losing the first match of the season.
However, David Raya's miraculous diving save kept the away team's goal safe. Then just 121 seconds later, Bruno Guimaraes had a super product from outside the penalty area that hit the net of the "Black Cats". Sunderland then rallied but they conceded another goal by Bukayo Saka in the 90+8 minute in a one-man situation.
Arsenal had truly stormy moments at the "Light" stadium, but once again Mikel Arteta's team stood firm. If Morgan Rogers had not had a super product in the London Derby in round 3, by this time the "Gunners" would have won all 4 matches without conceding a goal.

The question now is which team in the Premier League can stop Arsenal? Although the North London Derbys are always dramatic and fierce, Tottenham cannot be considered the team to stop the "Gunners" at this time. They have just set a bad record when for the first time in club history they could not score in the opening 4 matches. A summer investing more than 400 million pounds but only 2 points after 4 matches is an unacceptable result for Spurs.
Chelsea just lost to Arsenal in round 3 and they also could not beat Hull City in round 4, even at times being led. Meanwhile, Liverpool just had 2 victories against Ipswich (Premier League) and Atletico Madrid (Champions League) but could not beat Fulham (draw 0-0) even though the London team lost all 3 matches at the beginning of the season.
The team that can stop Arsenal is also not Aston Villa when they lost to the defending champion at home in round 2. In round 4, Unai Emery's team continued to suffer defeat against Nottingham and is now struggling in 19th place with only 1 point after 4 matches.
Newcomers, especially Hull City, have been playing very impressively since the beginning of the season, but if it is predicted that they can stop The Gunners, no one dares to confidently say it. The reigning Championship champion Coventry City lost miserably 0-3 to Arsenal on the opening day of the Premier League, Hull and Ipswich may not even dream of creating a shock.

The remaining two teams are from Manchester. Manchester United once defeated Arsenal last season when Michael Carrick took over at a time when the "Gunners" were racing for the championship very fiercely with Manchester City. However, after a near-perfect season when they also reached the Champions League final, Arsenal is now stronger than last season with very quality personnel being added. The lesson from last season is still there and Mikel Arteta will not be able to let Arsenal repeat their mistakes against Man United. Not to mention, the "Red Devils" are also a very erratic team and have never had stability that has reassured their fans for the past decade.
If Pep Guardiola is still leading Man City, the Etihad Stadium team will be considered the biggest rival. Pep left and left the legacy for Enzo Maresca and by this time the former champion is still playing well. Maresca has a philosophy similar to Pep and has also just been supplemented with many quality contracts. After 4 rounds, they are the only team to win all 4 matches out of the remaining 19 teams and still show the ability to compete fairly with Arsenal.

Arsenal's three most recent opponents, Chelsea, Napoli and Sunderland, are all very uncomfortable when they often organize deep defenses, even playing fiercely. However, Arsenal both won even though the scenarios were somewhat different. That is the bravery of the reigning Premier League champion and is aiming to win the Champions League for the first time.
