Arsenal's annual Emirates Cup tournament got off to a flyer for the home side with a 5-2 win over Benfica.A brace from Theo Walcott was complimented by strikes from Olivier Giroud, Alex Iwobi and an own goal and Arsenal looked hungry till the end to score plenty more.Alexandre Lacazette also played the last 20 minutes in front of the Gunners faithful, but fellow new boy Senad Kolisinac really stole the show after the left-sider was involved in three of the five goals.Even though the red half of north London leaked two goals on a rainy day at the Emirates Stadium, Wenger will have had plenty of reasons to be pleased with their victory.Another man who will have plenty to be pleased about is Walcott.The England international scored two goals that any striker would be proud of to cap off some slick team moves from the home side and his confidence was evident throughout the game.Kolisinac really made his first effort, but it was still a tidy finish on the volley from the former Southampton man.His second was another flowing Arsenal move, but instead of praising his striker instincts for the first two goals, many Arsenal fans tore into Walcott for missing a bit of a sitter to complete his hat-trick.As you can see from the clip below, Giroud's excellent hold-up play gave Walcott the chance from about eight yards out, but on his left-foot, he never looked confident.Natrually, Arsenal's fans had plenty to say about it on Twitter.

Back in March, Wenger insisted that Walcott had grown as a player in the last few years and explained why he has become so important to his side.

“He does better in the tactical part of his game and works hard defensively and offensively," Wenger said. "He has been less injured as well, that helps.

“He has turned up in big games as well, he can score goals in big games. He showed that against Bayern, he scored the goal and I think it was a penalty on him and he can influence games.

“The major quality of Theo is the quality of his receptions – that means he gets the ball in areas where he is extremely dangerous and that is a very intelligent part of a football player.”