Arsenal wanted a penalty for handball against Wilfred Ndidi with referee Mike Dean unmoved, but the equaliser came on the stroke of half-time after Kolasinac unselfishly squared to Welbeck with the goal gaping.
"We have had a better pre-season than last year and we have the confidence levels of a team that has won a European competition and returned to the Champions League".
In what has been a busy summer since the 2016-17 season ended, Arsenal have signed Lyon striker Alexandre Lacazette in a club-record deal and Bosnian defender Sead Kolasinac on a free transfer ahead of the new season.
"He thinks he can do more at football's highest level so we are having conversations and discussing the possibility of him staying for the second part of the season". "If that is going to mean better results and the title, I don't know".
The expectation-the hope, the dread-had been for an almighty clash in Manchester, Jose Mourinho and Pep Guardiola bringing the ferocity of their Spanish rivalry to the Premier League, matching competing ideologies against each other while trading barbs on an off-field propaganda war that would make the press-conferences almost as compelling as the football.
Chelsea's title success last season was thoroughly deserved and fascinating in the way it followed a tactical tweak, but it wasn't the program that had been billed.
Mahrez nearly equalized less than two minutes later in sensational fashion, with his volleyed attempt off a set piece going tantalizingly wide of Petr Cech's goal. West Ham's recruitment has been a mixed bag, from signing a proven goalscoring gem in Javier Hernandez to acquiring the infuriating Marko Arnautovic at great expense.
The rest of the Premier League teams will open up their campaigns over the next two days, but it's unlikely they'll match the entertainment value provided by Friday's opener in London.
Perhaps it is all just an overreaction and Chelsea will cruise to victory, but failure to win will continue to keep tongues wagging.
Jamie Vardy then capitalised on awful defending to twice put the Foxes ahead either side of Danny Welbeck's equaliser before Arsene Wenger sent on the cavalry. Last season two were not. "I just think he was very clear showing what he did last year was not enough for him".
"But I am not a difficult person to work with, in spite of sometimes it looks different or you want to make it look different".
There is a lingering feeling that all is not well at Stamford Bridge, despite being the current champions of England, and all eyes will be on Saturday's visit of Burnley.
David Moyes, who was sacked by United in April 2014 after a nightmare stint at Old Trafford, said his former side have a "really good chance" to win the Premier League. The pressure it's never a big problem.
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