Kayle vs Garen Top Matchup
Kayle Top wins 53.2% of 2,601 Low Elo games against Garen Top, +2.9 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.
Why Kayle is favored
Kayle can kite Garen with Celestial Blessing(W) and slow him with Radiant Blast(Q) after Decisive Strike(Q) is spent, then use Divine Judgment(R) to survive his execute if she casts it before his silence. That lets her deny Garen's all-in while continuing to scale from range.
How to play as Kayle
Hold Radiant Blast(Q) until Garen uses Decisive Strike(Q), then use Celestial Blessing(W) to widen the gap; if he reaches you, cast Divine Judgment(R) before his silence or execute lands.
Decisive Strike(Q) breaks Garen free from slows, so Radiant Blast(Q) is more useful for kiting after he has spent it; Celestial Blessing(W) adds movement speed for the retreat.
Divine Judgment(R) grants invulnerability, but Kayle needs to cast it before Decisive Strike(Q) silences her if she wants it to stop Garen's follow-up Demacian Justice(R).
How to play as Garen
Approach from a bush or flank when possible so Kayle has less time to kite with Q and W, and do not spend Demacian Justice(R) into her Divine Judgment(R).
Sources
These notes come from r/Kaylemains, checked against the champions' abilities.