Arsenal maintained their recent impressive form as they overcame a stubborn West Brom 2-0 at the Emirates on Monday night, courtesy of an Alexandre Lacazette double.
Gunners boss Arsene Wenger made two changes from the 0-0 draw with Chelsea, with Mohamed Elneny and Alexis Sanchez coming in for the injured Danny Welbeck and Alex Iwobi, who returned to the bench to leave Aaron Ramsey in a more advanced midfield role.
West Brom manager Tony Pulis made three changes from the side that drew 0-0 with West Ham, reverting to a back five with Allan Nyom, Jake Livermore and Hal Robson-Kanu replacing Chris Brunt, James Morrison and Matty Phillips as the Welshman looked for his first win away at Arsenal.
The home side had the first chance of the match when Sanchez, who was making his 150th appearance for the Gunners, flashed a freekick inches past the Baggies' far post with stopper Ben Foster rooted to the spot.
West Brom then had a massive penalty appeal turned down when Gareth Barry set free Jay Rodriguez, who was tripped by Shkodran Mustafi. Referee Bobby Madley either missed the foul or decided to play advantage, as Rodriguez saw his effort tipped on to the post by Petr Cech and Livermore was unable to convert the rebound.
The five at the back for Albion continued to contain and frustrate the Gunners, and another chance went begging when Elneny's floated pass was crossed in by Hector Bellerin, with Ramsey only able to head the ball over the bar under pressure from Jonny Evans.
The home side then took the lead when Sanchez's freekick was tipped on to the bar by Foster, Lacazette reacting first to head in to the empty net to put his side ahead with 20 minutes on the clock and ease the concerns of the majority of the Emirates crowd.
Pulis' side then had a number of golden opportunities to equalise before the break. Grzegorz Krychowiak's marauding run resulted in seeing a Rodriguez header hacked off the line by Nacho Monreal, before a Robson-Kanu header flashed across the face of Cech's goal with former Burnley forward Rodriguez just inches away from applying the final touch.
Former Gunners left-back Keiran Gibbs was then found by Krychowiak on the left and his cross caused havoc in the home penalty area - but Rodriguez was unable to capitalise on some uncertain defending from Bellerin, as the Gunners went into the break a goal to the good.
Lacazette nearly doubled his and his side's tally for the evening five minutes into the second half when Elneny teed him up just after the break, but he saw his goalbound effort deflected behind by Gibbs for a corner.
The Gunners continued to press and probe for their second but the away side held firm, looking to play on the break in search of an equaliser. With Pulis looking to inject some energy into his side, James Morrison and Salomon Rondon replaced the tiring Livermore and Robson-Kanu.
With 25 minutes to play a clumsy Nyom challenge on Ramsey meant the home side were awarded a penalty by Madley - Lacazette dispatching the spot kick past the despairing Foster to seal the points with his second goal of the match.
The former Lyon striker then had a glorious chance for his first hat-trick in English football when he sublimely bought down a Sanchez ball and took the ball round Foster, but could only blaze his effort over the bar from a tight angle.