Airbus can arguably claim to have secured the upper hand in the colossal American Airlines order, not simply because it will supply 56% of the 460 aircraft but because it cements its position in the highest ranks of US carriers.
While Airbus has achieved a presence within Delta Air Lines and Continental Airlines simply through their respective tie-ups with Northwest Airlines and United Airlines, the American deal - worth in the region of $35 billion - is an outright selection which ends Boeing's dominance at the US carrier, and means four of the top five US airlines will operate Airbus jets.
Airbus has been chasing the Boeing 757 retirement market with its A321neo, in particular, and would have seen American's fleet of 124 757s as a target.
It is unclear whether Boeing would have been relegated to a minority player in the deal but for its decision to offer American the prospect of a re-engined 737.
But Airbus had claimed earlier this year that its US rival would be forced into a re-engining of the 737 if it faced the prospect of losing a major customer to the A320neo, launched towards the end of 2010.
The European airframer, citing previous aircraft development parallels, had strongly suggested that Boeing would not follow through with talk of a new single-aisle aircraft.
Despite the taunting from Airbus, Boeing seemed to be leaning towards an all-new design, notably emphasising a belief that its current 737 would be able to hold its own against the A320neo - at least enough to buy valuable time to develop an all-new twinjet.
Chief executive Jim McNerney had described the all-new jet as the "leader in the clubhouse" in terms of the way Boeing was thinking.
Having scuppered any prospects for an announcement at the Paris air show, Boeing appeared to indicate that it would take several more months to reach a decision between the two options - leaving questions as to the trigger behind today's disclosure.
But an all-new aircraft would have required heavy investment and potentially made Boeing vulnerable in the meantime, particularly given the unexpected popularity of the A320neo.
Re-engining the 737 is less ambitious, at a time when Boeing is still reeling from delays to 787 and 747-8 development. Opting for a lower-profile programme could also enable Boeing to concentrate on upgrading its 777, and capitalise on recent delays to the Airbus A350 programme.
If American has effectively forced Boeing's hand, it might also have done the US airframer a favour by providing clarity for other competitions - such as that with Delta Air Lines - as well as putting up a further barrier to the Bombardier CSeries, which might have gained from a weak Boeing position ahead of an all-new narrowbody.
Unlike the situation on the A320neo, CFM is to retain its position as the sole powerplant provider for the re-engined 737, the manufacturer has confirmed, closing off half of the American deal to Pratt & Whitney which will only be able to vie for the A320neo portion.