A terrible start has put Arsenal into a massive hole, and they're going to need to put together a brilliant second half performance to salvage this Champions League tie. Bayern Munich never looked much like conceding after the opening minutes, struck early, then piled on the misery to carry a 2-0 lead into the halftime break.
Arsenal got off to the brighter start of the two teams, creating a couple of half-chances in the first five minutes. Jack Wilshere started both moves with great balls out wide, but a Santi Cazorla cross in the 3rd minute was claimed by Manuel Neuer, while a similar move through Walcott produced a corner that Arsenal were unable to make anything out of.
In the 7th minute, Toni Kroos struck from 20 yards out to give Bayern the lead. A low cross from Franck Ribery to the top of the penalty area wasn't picked up by anyone, as Mikel Arteta failed to track Kroos and Per Mertesacker failed to step up. With no one closing him down, Kroos took a rip and placed a brilliant shot into the back of the net to notch a big away goal.
Things got worse for Arsenal in the 21st minute. Set piece defending has been an issue for Arsenal all season, and they looked horrible in conceding their second. Daniel van Buyten was uncontested as he rose up to head on goal at the near post, and Wojciech Szczęsny made a save. No one was watching Thomas Müller, though, and the Bayern attacker poked in the rebound.
Both sides had solid spells of possession for the rest of the half, with Arsenal having more of the ball, but Bayern backed off following their second goal and looked content to play a more defensive game. Just before the end of the half, they hit on a counter and Mario Mandžukić missed a close-range header by inches, failing to capitalize on an opportunity that would have all but ended this tie. Arsenal are going to need something special to get back in this, and they're going to need to avoid conceding again as well.