The international community swung into action on Monday and Tuesday to diffuse the fallout from this rift.
Recent diplomatic activity highlighted fears of potential consequences for the Syrian Geneva peace talks set for later in January.
It was anticipated for Iran and Saudi to begin to converge following their agreement to participate in the Geneva talks.
Yet that may have been just a pipe dream.
It was unlikely, even before the recent diplomatic rift, that Iran was willing to support any process that saw Assad leaving office immediately, or that Riyadh was willing to support a process that involved Assad's staying.
Despite lip-service proclaiming the desire for resolution, the foreign policies of both nations have resolutely remained fixed around two mantras: Iran says Assad must stay, Saudi Arabia says Assad should go.
In the lead-up to Geneva, there has been no real indication that either country is willing to break with their mantra.
Although Iran indicated a possibility for retracting from its position that Assad must remain, its foreign minister, Amir Abdollahian, was quoted in October saying Iran "does not insist on keeping Assad in power forever".
But what seemed a significant Iranian shift may not have been. The base principle that Assad stays in power during a "transitional phase" remains a core Iranian position.
For Saudi Arabia, Assad staying even during a 'transitional' phase was unacceptable from the onset.
In the statement of principles produced by Syrian opposition members in Riyadh, the same position was reiterated.
While the statement called for a new "pluralistic regime that represents all sectors" in Syria, it stressed Assad and his aides have no part to play in any transitional period.
Both countries want to be seen willing to participate in a peaceful resolution of the Syrian crises, but are not so willing to compromise core positions.
At the end of 2015, it was eminently preferable for both rivals to see Geneva fail than see one of their core principles of foreign policy upended.
The recent diplomatic rupture could however have one significant impact on the Syrian peace negotiations in Geneva.
With both rivalries stepped in a heated ideological and propagandist war, neither would be willing to take any step that could be constructed as a defeat of one and victory for the other.
'Concessions' from either nation maybe ruled out entirely.
In the lead-up to the conference, there were indications, at least for the short-term, parties were willing compromise on certain areas beyond their core positions.
Notably, the Riyadh Conference's indication that Assad could remain at least until a transitional government was formed was considered a significant shift.
Now however, with the blowing into the open of the Saudi-Iranian rivalry, even smaller gestures may likely to be resisted.
Neither country will want to risk making any gesture that could be construed as 'bending' or 'weakness' in the face of the other.
Instead, both may actually come to favour the current status quo in Syria, where the Syrian regime and opposition groups are unable to overcome the other.
With neither country directly affected by events in Syria, the continuation of a continuous 'military' solution affords no loss of symbolic capital in the short-term.
A division of Syria into 'rump-state' of the Syrian regime centred on Damascus and the Mediterranean coastline and a 'rebel-state' comprising opposition controlled areas in the North and South may, as a consequence of recent events, have become an increasingly preferable outcome of the crisis to both Saudi and Iran.