Arsenal increased the pressure on Sunderland manager David Moyes with a comfortable victory over a Black Cats side who remain bottom of the table and without a Premier League win this season. Alexis Sanchez put the Gunners ahead when he got in front of defender Lamine Kone to head in Alex Oxlade-Chamberlain’s cross. The dominant visitors had a strong penalty appeal turned down after Sanchez looked to have been brought down before Jermain Defoe equalised from the spot after keeper Petr Cech had fouled Duncan Watmore. However, Arsenal reasserted their authority and lead with three goals in six minutes and 20 seconds. Olivier Giroud came off the bench to guide in a shot and then headed in a Mesut Ozil corner, while Sanchez’s close range effort was the signal for the home fans to start streaming out of the Stadium of Light.

The win moved Arsenal top of the Premier League – but whether they stay there depends on how Manchester City and Liverpool fare in their later games. Arsenal boss Arsene Wenger wanted a win in the early Saturday game to put pressure on his side’s rivals and his players duly delivered. The Gunners were missing the in-form Theo Walcott, but Oxlade-Chamberlain, who scored twice in the midweek EFL Cup win over Reading, competently filled the void. He provided the cross for Sanchez, starting up front instead of Giroud, to head in the opener and the England midfielder has now been involved in seven goals in his past eight games in all competitions, with four goals and three assists. Ozil had a chip saved when clean through and the Gunners were punished for failing to turn their dominance into further goals when Defoe equalised. However, Arsenal regrouped and recovered with a late burst of goals and are unbeaten in 14 matches.

Arsenal were still smarting from referee Martin Atkinson not awarding them a penalty for Kone appearing to pull back Sanchez when Defoe gave Sunderland hope. Wenger sent on Giroud, who was playing his first league game since 24 September following a toe injury, and he scored with his first two touches of the game. “I have been lucky today, I had great assists from my team-mates,” said France striker Giroud, who has scored seven goals in his last seven appearances against Sunderland in all competitions. “It is a big time for me coming back from a tough injury and I’m very happy to be back on the pitch.” Arsenal have lost just one of their past 20 top-flight games (12 wins and seven draws) Alexis Sanchez has been directly involved in eight goals in his past eight Premier League appearances (five goals, three assists).

Alex Oxlade-Chamberlain scored twice as Arsenal extended their unbeaten run with a hard-fought EFL Cup win against Championship side Reading. The England midfielder opened the scoring when he skipped into the box and drilled into the bottom corner. Reading almost equalised when Callum Harriott’s deflected shot landed on top of Emiliano Martinez’s goal. Arsenal dominated after half-time, with Oxlade-Chamberlain’s deflected shot completing a 14th game without defeat. Oxlade-Chamberlain, 23, has struggled to claim a regular starting place in Arsene Wenger’s first-choice side during their fine start to the campaign.

He has completed 90 minutes on just two occasions this season, but staked his claim for a bigger role with the standout performance in a much-changed Arsenal team. While there was little to remind the Emirates Stadium crowd of Arsenal’s memorable 7-5 win when the teams met in this competition in 2012, it maintains the Gunners’ hopes of winning the League Cup for the first time since 1993. Reading acquitted themselves well for the most of the contest, but were put on the back foot when a sloppy pass from keeper Ali Al-Habsi allowed Oxlade-Chamberlain to win back possession high up the field and then open the scoring. Al-Habsi partially redeemed himself with several saves after the break, but was powerless to stop the second which deflected off Royals defender Jordan Obita to seal victory.

Arsenal’s six-match winning run in the Premier League came to an end against Middlesbrough but a point was enough to move them top of the table. Manager Arsene Wenger – celebrating his 67th birthday – watched his side dominate possession but underwhelm in the final third. The Gunners managed five efforts on target, but only one worried Boro keeper Victor Valdes when he pulled off a great one-handed stop to deny Alexis Sanchez. Aitor Karanka’s side defended brilliantly and, despite conceding much of the possession to the home side, created the better chances. Arsenal keeper Petr Cech blocked Gaston Ramirez’s header, twice denied the outstanding Adama Traore and also saved from Alvaro Negredo. The home side briefly thought they had won it in injury time but Mesut Ozil’s effort was rightly ruled out for offside. Despite remaining in 17th place, Boro should be buoyed by the display and unexpected result.

The invitations have been sent out, the hall is decorated and the party food is prepared – but then only a handful of guests turn up and music is barely audible. That is how birthday boy Wenger must have felt at the final whistle as his side, who have been in tremendous form, had their wings clipped by a resilient and disciplined Boro. Karanka’s side might have only had 25% of the possession but the gameplan was to set up a defensive wall across their area and hit the Gunners on the counter-attack. Wenger’s men tried almost everything. After failing to walk through the Boro defence they tried to play the ball over the top, but lacked accuracy. When they did have a sight of goal they lacked conviction. Sanchez tested former Barcelona team-mate Valdes from 20 yards but should have done much better with one from half that distance. They mustered a final set of attacks in the closing moments and had the ball in the net when Ozil poked in, but the German was clearly offside.

Finding goals was Middlesbrough’s problem coming into this game having scored only seven in the league. Loan signing Negredo netted on the opening day of the season but has been off-key since. At the Emirates he should have beaten Cech with a low shot and then, with moments remaining, he allowed Laurent Koscielny to tackle him in the area. Both Gaston Ramirez and in particular Traore impressed in midfield, with Karanka’s counter-attacking plan suiting the pacy Spaniard, who twice threatened with runs from his own area. One of those ended with a shot that Cech had to push away and another saw him play in Negredo for that late chance. The 20-year-old also had another strike saved by the Gunners keeper in the first half. If Boro build on this display and start finding the net then they might avoid a relegation battle at the end of the season.