Chancellor Angela Merkel was celebrated as the queen of Europe in the German press after the summit deal at dawn, but the tag-team negotiating style of Poland's ruling Kaczynski brothers has left visible strains in ties with Warsaw.
The conservative Frankfurter Allgemeine compared Dr Merkel to Otto von Bismarck for mastering the "art of the possible", while Bild tabloid blamed the summit's near-disaster on the "poisonous Polish dwarfs".
From a Berlin perspective, the secret of Dr Merkel's success was her "confessional" - the German presidency suite on the Justus Lipsius building's fifth floor.
Polish president Lech Kaczynski was, with four trips, the most frequent visitor. During these confessionals, Dr Merkel employed tea, sympathy and every argument she could think of to win him over, from their shared memory of communist rule to her Polish grandfather.
German officials suggested yesterday it was her final call in the political poker - to proceed with treaty talks without Poland - that broke the deadlock.
"When you come to a point like that, you analyse soberly where you stand and we realised we had come to a point where we couldn't get any further," said one leading German diplomat privy to the talks. "After the statement we did notice new movement in a situation that had stiffened."
The official conceded a "certain tension" grew in the German delegation throughout the evening as apparent deals with Mr Kaczynski were torpedoed by his prime minister brother in Warsaw "but considering our particular relationship to Poland we cannot comment on it - we leave the reactions to others", the official said.
German newspapers agreed that disaster had been averted for the moment, but many warned that future problems with Poland could not be ruled out.
The Frankfurter Allgemeine said the difficulties of the summit arose from the sense of entitlement of the Kaczynski brothers to funds from the EU - read Germany - with no strings attached.
"Warsaw sees itself as Germany's moral creditor and German guilt as something that can never be put right, practically irredeemable . . . [ but] one has to ask whether Polish neuroses are now Europe's problem," it said.
"Although the young, western-oriented Poland doesn't feel the Kaczynski phantom pain, the politics of polarisation always casts a spell, particularly when, as the final result in Brussels shows, a quarrelsome manner is shown to be successful."
Unsurprisingly, the summit result was highly praised by Dr Merkel's own Christian Democrats. "Our chancellor has managed a diplomatic masterwork," said parliamentary leader Volker Kauder. There was grudging praise from her Social Democrat (SPD) coalition partners, who have watched with growing envy Dr Merkel's solo run of success during Germany's double EU-G8 presidency. SPD leader Kurt Beck praised Dr Merkel for overcoming an "unbelievably difficult situation" to agree a treaty deal.
"That is worth our respect and support," he said.
SPD parliamentary leader Peter Struck sniped that Dr Merkel would soon lose her lustre. "Now she has to do domestic politics again," he said.