A number of defensive mistakes lead to Seattle’s first goal:

Things are organized quite well as Seattle’s goal-scoring sequence beings. From left to right: Palmer has Montero marked; Danso is free; Horst is on Tiffert (who had just made an attempt to break down field and in this screenshot is returning to an onside position); Wallace has Rosales; Chara is putting pressure on Johnson who had come back deep to show for the ball; Songo’o has Johansson; Jewsbury is watching Alonso; Nagbe is on Evans. It’s a good defensive setup, and although Tiffert and Johnson have momentarily “swapped” spots, there shouldn’t be any cause for alarm or confusion at this point. But as Johnson drops the ball back to Alonso, things begin to break down…

First, there’s simply not enough pressure on the ball. Jewsbury had dropped off when Johnson had the ball to help cover in case Chara got turned—that’s basic 2v2 defending—but he simply doesn’t close down quickly enough when the ball was passed back to his man. Second, Johansson begins his run down the far sideline and Songo’o is oblivious. He’s simply checks out for a split second and gets caught ball-watching. Now in-and-of-itself that shouldn’t have been a huge problem, Wallace would pick up the runner and Songo’o would slide over and watch Rosales, but there’s a third problem. For some reason, whether a lack of communication or just lazy defending, no one actually marks up on Tiffert. Horst should be right in his back pocket, but he’s not. Wallace gets frozen trying to guess which pass Alonso is going to make when he notices Johansson streaking through…

Wallace elects to try and pick off the pass instead of staying with the runner. And since Horst isn’t marking tightly, he ends up in no-man’s land and Johansson gallops forward with no one tracking him. Now even at this point, despite the mistakes that have been made, Horst could still salvage this. But he, like Palmer, assume that Wallace will win the ball and they relax for a moment. Tiffert cheekily dummies the ball and both Horst and Palmer get caught flat-footed. I mention Palmer at this point because it’s important to note his role here as well. Up to this point he’s done everything perfectly. He’s stayed with his man, he’s tight enough to close down if the ball should come his way, he can see both his man and the ball, and he has an excellent view across the pitch to see everything developing in front of him…

So why on earth is Montero a full step beyond him just a second later?! As we all know this ends with a Futty own goal, but had he not put the ball in the back of the net, Montero would have been able to do it just as easily.

As is so often the case, there are a number of things that go wrong, and eliminating any one of them could have easily put an end to the goal-scoring opportunity.