Vayne vs Irelia Top Matchup
Vayne Top wins 45.2% of 504 Low Elo games against Irelia Top, -1.3 points vs expected, 2-patch window 26.19-26.20.
Researched on LoL patch 26.20. Tips are written to hold at any rank; stats come from Low Elo ranked games up to patch 26.20.
How to play as Vayne
When Irelia dashes onto you, stand near a wall and time Condemn for the end of her Q animation so the knockback pins her into the terrain.
Before your first item, stay to the side of the minion wave and use Tumble to avoid Irelia's stun; don't give her a clear E or R setup.
Irelia's Q places her behind her target at the end of the dash; Vayne can use Condemn near a wall to knock her into it and stun her.
Sources
These notes come from r/vaynemains, checked against the champions' abilities.