Last night was a win for Obama and probably a bigger win than in the second debate, but it was of less import.
The debate was meant to be about foreign policy (though it strayed into economic policy, largely because that's where Romney wanted to take it). Obama did a successful job of presenting himself as the grown-up in the room. The president was sure-footed, authoritative, and aggressive in a controlled and effective way. There's no doubt that he's at his most comfortable in this area, and most confident that his opponent doesn't understand the issues in the way he does. His consistent line of attack was that Romney had no strategy ("all over the map") and constantly changed his positions on political whim. Obama combined this attack with some effective condescension, the most vivid example of which (see above) was in response to Romney's complaint that the navy has fewer battleships than it did. Obama replied, "We also have fewer horses and bayonets" (Note "fewer", because actually the U.S army still uses bayonets, fact fans).
Romney played a defensive game, as Obama did in the first debate (though Romney played it better). He often agreed with the president's positions, for example on Libya, Egypt and Syria, with qualifications. His biggest concern seemed to be calming the fears of voters (female voters in particular?) that he represents a return to the bellicosity of the Bush era. One of the first things he said was, "We can't kill out way out of this mess", as a critique of Obama's terrorism policy. How odd to hear to a Republican candidate accuse a Democrat of being too eager to kill America's enemies, and advocate soft power. He said he didn't want more wars, and sought "a peaceful planet". He wasn't at ease: he often gave meandering, fast-talking, confusing answers, and the contrast with his fluency on economic issues was striking. But he wasn't awful.
Overall, Romney's aim was to look competent, rather than knock the president out or blow voters away with his amazing ideas. Surprisingly, he made no mention of Benghazi, perhaps judging that the risk of another screw-up was too high given the detail involved. But then, his campaign is probably calculating that the daily news reports of fighting and chaos in Libya and Syria are already doing the job of undermining the president's credibility, and that all Romney has to do is be perceived as a safe pair of hands. Despite losing the debate on style and substance, his advisers may well feel he just about accomplished that job last night.
This election is not about foreign policy, so this debate was always likely to have the smallest impact of the three. Whether you think last night was good for Romney or good for Obama depends on where you judge the race to be. If the overall momentum is still with Romney then it was excellent: a narrow loss on foreign policy is as good as a draw is as good as a win. If the race has stabilised behind a narrow Obama lead (which is where I think it is, though it's hard to tell) then Romney may come to regret not taking more of a risk. The clock is running down.
(Full debate here).