Bayern Munich may or may not become the first team to retain the Champions League, but it is a battle with the footballing fates that is almost certain to survive this tie. When Bayern are good, they're great, but when they're only so-so they're still more than enough, as they were during a 2-0 defeat of Arsenal at the Emirates that was dampened by a debatable red card for Wojciech Szczesny in the first half.
A year on from the 3-1 victory here last season that announced a thrilling three-month surge by Jupp Heynckes' champion-team-in-waiting, Bayern were no more than moderately, adequately irresistible at the Emirates, and lucky not to go a goal behind in the opening 10 minutes as Mesut Özil missed a penalty.
As it was Philipp Lahm produced a routinely superb performance in two positions, Toni Kroos was commanding behind the central striker and by the end Bayern had made 791 passes to Arsenal's 160 and had 73% possession of the ball. It is a measure of the sense of top-down strength in reserve at this grand regional superpower of a club that a 2-0 away victory that saw the entire second half played out as a neck-cramping assault on the home goal still seemed no more than adequate in the circumstances.
This was an agreeably widescreen occasion from the start on a cold, clear north London night that saw the Emirates away section crammed with the usual booming throng of roving Bayern-ites, and the entire stadium crackling before kick-off with a sense of rare-event glamour. Here they came, the world's best football team in their austere deep grey-blue, as ever a surprisingly tall and powerful-looking bunch of beautifully composed world champion footballers.
This Bayern team has an almost self-conscious air of unhurried all-star conviction about it, and they were on the attack immediately. Kroos, who doesn't so much run as trot about like a cosseted pony, drawing a leaping one-handed save from Szczesny. After which it was briefly all Arsenal.
In fact, Arsenal started like Bayern tend to start in this competition, producing in the first 15 minutes their most relentlessly mobile football since entering ahead of time that familiar English state of stumbling, teeth-gritting, game-to-game fatigue that in most cases tends to set in around Easter.
Jack Wilshere in particular was bright, producing the nutmeg and nudging through a pass that allowed Özil to win so beautifully the penalty he would then so horrendously miss, very deliberately sending Manuel Neuer the right way before effectively placing the ball on to his raised palm.
Bayern weathered the storm with a little luck and a familiar sense of composure. They have played five fewer matches than Arsenal since the start of December, helping Pep Guardiola's team to retain a degree of freshness that is vital to their hard-running, high-pressing, physically relentless style.
And this is really the key to Bayern , who can drop the pace and hide the ball as they did here in the first half after that early scare, Javi Martínez and Thiago Alcântara steadily conducting possession and Lahm and David Alaba pushing fearlessly up the pitch; but who have above all the ability to produce those distinctive Bayern attacking surges, a collective stretching of the legs like a 10,000-metre runner destroying the field by producing out of nowhere a leg-cramping mid-race lap time.
There was a Guardiola-hallmarked fluidity in the repeated exchange of flanks by Arjen Robben and Mario Götze, although it was the familiar Robben dart in from the right that led to Szczesny's sending off, a straight red card for denying a clear-ish goalscoring opportunity. The ball was running away.
The goalkeeper had no choice but to challenge. A yellow card and a penalty would surely have been enough. David Alaba seemed an odd choice of penalty taker in this champion team. His run-up was always a little meek and he duly side-footed his kick against a post.
Half-time arrived with Bayern a man up and what had seemed likely to be a midfield-fetishists dream all but ruined by the sending off. This Guardiola-issue Bayern have at times resembled little more than a single giant roving midfield, but here they had lined up initially in respectfully orthodox fashion, with Lahm at right-back and Mario Mandzukic re-installed as a genuine No9.
Guardiola moved Lahm into midfield at the start of the second half, introducing a little extra drive as the Bayern surge duly arrived. In the end nine minutes of smothering attack was all it took, the opening goal beautifully struck by Kroos, who took a pass from Rafinha and with his right foot very precisely persuaded the ball into the top corner.
It is perhaps final proof of their riches that there could be a suggestion Bayern might think about letting this delightfully upright multi-purpose attacking midfielder leave. Although, as the blue swarm continued to toy with Arsenal's entrenched defensive line and Mandzukic gave way to Thomas Müller – as of this week the world's greatest substitute – it was tempting to conclude Bayern were simply crunching through the high gears here.
Arsenal fought gamely and were applauded from the pitch at the end by their supporters. But Müller's headed second goal effectively killed this tie at the end of a first leg that simply fell away, clouded by one decisively harsh refereeing decision and also by the sense here of opponents who already have the game weighted quite enough in their favour, and who remain irresistible even at half-speed.