by a large [slim, narrow, small] majority
大差[僅差]で
by a lucky chance
幸運にも
by a margin of 500 votes
500票差で
by a [some] miracle
奇跡的に
by a nose
鼻差で;わずかな差で,やっと
by a pure coincidence
単なる偶然の一致で
by a quirk of fate
運命の気まぐれから,まったくの偶然から
by a roundabout route
回り道をして
by a shorthead
《競馬》馬の頭より小さな差で;僅差で
by a swift dodge to the left
左へすばやく身をかわして