This is the first time I've ever experienced this. I thought I lost the battle after being so close. Splinterlands has a game mechanic called fatigue that helps determine a winner when it seems that the match has come to a stale mate. Watch the game replay linked below to see what I mean.
https://splinterlands.com?p=battle&id=sl_98c199d50f6b658da0bd18d3ca1c8c4b&ref=tscott
Once the match reaches round 20, the game introduces fatigue into the battle. Each opponent will receive damage after each round in order to help determine the winner. In this case, it saved me and got me a win.