Vine hit Android devices last week, and less than a week later, surpassed Instagram in total Twitter shares.
The six-second video-sharing app launched with 1.8 million Twitter posts on 3 June, compared to Instagram's 2 million mentions on the same day, according to Topsy's analytics.
By 7 June, Vine was in the lead, having climbed to 2.5 million — higher than the photo-filtering app's 2.2 million. Vine peaked on 8 June, with about 2.8 million mentions, clobbering Instagram, which earned 2.3 million on the same day.
Both services saw a drop-off on Sunday, and fell into sync by Monday, with Vine barely in the lead, according to Topsy's analytics, which reported a 21,000-post difference between the two sites.
In recent months, Instagram has had a rather contentious relationship with Twitter, which owns Vine.
The fight dates back to July 2012, when Twitter removed Instagram's access to its API, meaning the "Find Twitter friends" option disappeared from Facebook-owned Instagram. By December, Instagram pulled support for Twitter Cards, which allowed Instagram photos to show up within tweets.
Twitter released Vine for iOS in late January, several months after acquiring the video startup. The app allows users to create six-second looping videos, then share them on Twitter and Facebook.
It launched for Android earlier this month on Google Play, where it is ranked in fourth position among the top-rated free apps — Instagram comes in one place below.