Theo Walcott Arsenal
Arsenal forward Theo Walcott celebrates after scoring his 100th career goal in the 3-1 win over Hull City in the Premier League, September 17, 2016Reuters

Arsenal made life rather difficult for themselves again, when they should have had a stroll at the KCOM Stadium, while Pep Guardiola's Manchester City put on another imperious performance on the day in which the champions Leicester City had record signing Islam Slimani to thank to get them back to winning ways in the Premier League.

Utterly dominant from the start, Arsenal had chance after chance to put the game to bed early, but failed to, giving the home fans and the home team Hull City, down to ten men in the first half, hope of getting something out of the game.

However, in the end, the Gunners won 4-1, with Alexis Sanchez, with a brace, Theo Walcott and Granit Xhaka scoring the goals. The man who cannot stop scoring – Robert Snodgrass – knocked in a penalty, conceded by Petr Cech, for Hull's only goal of the match.

The game should have been out of sight by halftime, but Arsenal's profligacy and some wonderful saves from Eldin Jakupovic kept it within touching distance for Hull. After Sanchez opened the scoring in the 17th minute, slightly fortuitously, as a shot from Alex Iwobi went in off a deflection from the Arsenal forward, the away side should have gone 2-0 ahead, but Mesut Ozil shot high with the goal gaping off a rebound, following a brilliant low save from Jakupovic to deny the equally excellent Iwobi.

Arsenal then threw away another chance to go into cruise control when Sanchez, surprisingly stepping up to take a penalty with Santi Cazorla on the pitch, shot weakly, allowing Jakupovic to pull off another save. The sequence that led to the penalty, though, was a big talking point, with Jake Livermore, the former Tottenham layer, given a straight red card by referee Roger East. The handball was never in doubt, with Livermore sticking out his left hand to stop a goalbound shot from Francis Coquelin, but Jakupovic, behind the Hull midfielder, might have stopped the goal, leading to questions being raised on the red card decision.

However, with Hull forced to play with ten men for 50 minutes, they would have been fairly satisfied to go into the break only 1-0 down, but that satisfaction would not last too long, with Walcott, courtesy a delightful chip over the goalkeeper, off an even better assist from Iwobi, making it 2-0 for his 100th career goal.

When Snodgrass converted a penalty on 79 minutes after Cech brought Dieumerci Mbokani down, there were a few nerves, but those nerves were settled when Sanchez completed his brace in the 83rd minute, firing into the roof of the net after Walcott was stopped by Jakupovic.

The icing on the cake came from Xhaka, who scored the best possible debut goal, a thunderbolt from 35 yards out in the second minute of stoppage time.

At the Etihad, Manchester City maintained their 100% record with a comfortable-as-they-come 4-0 win over Bournemouth. Despite Jack Wilshere starting for his new club, City showed their ruthlessness up front, particularly on the counterattack, with Kevin De Bruyne, Kelechi Iheanacho, Raheem Sterling and Ilkay Gundogan, another first-time Premier League goalscorer, all netting in a 4-0 win.

The only dampener on an otherwise perfect day was a red card for Nolito four minutes from time.

At the champions' den, Slimani brought the roof down with a brace, both via headed goals, while the third came from a Ben Mee own goal as Leicester ran-out 3-0 winners over Burnley.

In the fourth match of the day, Tony Pulis had some of the pressure eased off him with a 4-2 win over West Ham.

Nacer Chadli, with a double, Salomon Rondon and James McClean gave West Brom a 4-0 lead, and while Michail Antonio and Manuel Lanzini netted for West Ham to spark the hopes of a comeback, it was too tall a mountain to climb.