Unai Emery made a number of questionable changes to Arsenal's starting XI for Saturday's north London derby at Wembley.Mesut Ozil, who had fantastic game against Bournemouth in midweek, dropped to the bench and so too did Lucas Torreira, Sead Kolasinac and top goalscorer Pierre-Emerick Aubemayang.Alex Iwobi, Granit Xhaka, Shkodran Mustafi and Alexander Lacazette started in their place against Tottenham as Emery also changed formation from 3-4-2-1 to 4-2-3-1.Emery has made it abundantly clear that none of his players are immune from being dropped, regardless of the form they're in, but one man who has become a constant is Bernd Leno.Leno joined Arsenal from Bayer Leverkusen last summer for £19m but started the season as second-choice goalkeeper behind Petr Cech.He eventually cracked the starting line-up in October when Cech suffered an injury during a 2-0 win over Watford.Since then Leno has started every Premier League game for Arsenal and even though the German has made a few mistakes, he's proved a solid signing.And against Spurs he showed exactly why Emery brought him to the club with a stunning double save - one of which was a save of the season contender.Arsenal took the lead through Aaron Ramsey in the 16th minute and looked relatively comfortable at the back throughout the first half.But two minutes before the break, Harry Kane clipped a pass over the top of Arsenal's defence for Christian Eriksen, whose shot was superbly stopped by Leno.The ball then fell to Moussa Sissoko, whose powerful shot from just inside the box was destined for the back of the net but somehow parried over the bar by Arsenal's goalkeeper. Check it out.

Fantastic piece of goalkeeping from Leno, who did extremely well to get back to his feet after stopping Eriksen to then deny Sissoko's shot through a body of players.

Tottenham later scored through a Harry Kane penalty after the England international was pushed by Mustafi at a free-kick. He was offside, but the linesman missed it.