diff --git a/include/constants/pokemon.h b/include/constants/pokemon.h
index c375bbdd10..a7f0e3e4ed 100644
--- a/include/constants/pokemon.h
+++ b/include/constants/pokemon.h
@@ -379,6 +379,7 @@
 #define EVO_SPECIFIC_MAP                  32     // Pokémon levels up on specified map
 #define EVO_LEVEL_NATURE_AMPED            33     // Pokémon reaches the specified level, it has a Hardy, Brave, Adamant, Naughty, Docile, Impish, Lax, Hasty, Jolly, Naive, Rash, Sassy, or Quirky nature.
 #define EVO_LEVEL_NATURE_LOW_KEY          34     // Pokémon reaches the specified level, it has a Lonely, Bold, Relaxed, Timid, Serious, Modest, Mild, Quiet, Bashful, Calm, Gentle, or Careful nature.
+#define EVO_CRITICAL_HITS                 35     // Pokémon performs specified number of critical hits in one battle
 
 #define EVOS_PER_MON 10
 
@@ -387,6 +388,7 @@
 #define EVO_MODE_TRADE      1
 #define EVO_MODE_ITEM_USE   2
 #define EVO_MODE_ITEM_CHECK 3 // If an Everstone is being held, still want to show that the stone *could* be used on that Pokémon to evolve
+#define EVO_MODE_BATTLE_SPECIAL 4
 
 #define NUM_MALE_LINK_FACILITY_CLASSES   8
 #define NUM_FEMALE_LINK_FACILITY_CLASSES 8
diff --git a/src/battle_main.c b/src/battle_main.c
index 479cafae6a..ca59ff86ef 100644
--- a/src/battle_main.c
+++ b/src/battle_main.c
@@ -115,6 +115,7 @@ static void HandleEndTurn_MonFled(void);
 static void HandleEndTurn_FinishBattle(void);
 static void SpriteCB_UnusedBattleInit(struct Sprite* sprite);
 static void SpriteCB_UnusedBattleInit_Main(struct Sprite *sprite);
+static void TrySpecialEvolution(void);
 
 EWRAM_DATA u16 gBattle_BG0_X = 0;
 EWRAM_DATA u16 gBattle_BG0_Y = 0;
@@ -237,6 +238,8 @@ EWRAM_DATA bool8 gHasFetchedBall = FALSE;
 EWRAM_DATA u8 gLastUsedBall = 0;
 EWRAM_DATA u16 gLastThrownBall = 0;
 EWRAM_DATA bool8 gSwapDamageCategory = FALSE; // Photon Geyser, Shell Side Arm, Light That Burns the Sky
+EWRAM_DATA u8 gPartyCriticalHits[PARTY_SIZE] = {0};
+EWRAM_DATA static u8 sTriedEvolving = 0;
 
 void (*gPreBattleCallback1)(void);
 void (*gBattleMainFunc)(void);
@@ -2999,6 +3002,7 @@ static void BattleStartClearSetData(void)
         gBattleStruct->usedHeldItems[i][0] = 0;
         gBattleStruct->usedHeldItems[i][1] = 0;
         gBattleStruct->itemStolen[i].originalItem = GetMonData(&gPlayerParty[i], MON_DATA_HELD_ITEM);
+        gPartyCriticalHits[i] = 0;
     }
 
     gSwapDamageCategory = FALSE; // Photon Geyser, Shell Side Arm, Light That Burns the Sky
@@ -5154,9 +5158,16 @@ static void FreeResetData_ReturnToOvOrDoEvolutions(void)
         gIsFishingEncounter = FALSE;
         gIsSurfingEncounter = FALSE;
         ResetSpriteData();
-        if (gLeveledUpInBattle && (gBattleOutcome == B_OUTCOME_WON || gBattleOutcome == B_OUTCOME_CAUGHT))
+        if (!(gBattleTypeFlags & (BATTLE_TYPE_LINK
+                                  | BATTLE_TYPE_RECORDED_LINK
+                                  | BATTLE_TYPE_FIRST_BATTLE
+                                  | BATTLE_TYPE_SAFARI
+                                  | BATTLE_TYPE_FRONTIER
+                                  | BATTLE_TYPE_EREADER_TRAINER
+                                  | BATTLE_TYPE_WALLY_TUTORIAL))
+            && (gBattleOutcome == B_OUTCOME_WON || gBattleOutcome == B_OUTCOME_CAUGHT))
         {
-            gBattleMainFunc = TryEvolvePokemon;
+            gBattleMainFunc = TrySpecialEvolution;
         }
         else
         {
@@ -5174,6 +5185,26 @@ static void FreeResetData_ReturnToOvOrDoEvolutions(void)
     }
 }
 
+static void TrySpecialEvolution(void) // Attempts to perform non-level related battle evolutions (not the script command).
+{
+    s32 i;
+
+    for (i = 0; i < PARTY_SIZE; i++)
+    {
+        u16 species = GetEvolutionTargetSpecies(&gPlayerParty[i], EVO_MODE_BATTLE_SPECIAL, i, SPECIES_NONE);
+        if (species != SPECIES_NONE && !(sTriedEvolving & gBitTable[i]))
+        {
+            sTriedEvolving |= gBitTable[i];
+            FreeAllWindowBuffers();
+            gBattleMainFunc = WaitForEvoSceneToFinish;
+            EvolutionScene(&gPlayerParty[i], species, TRUE, i);
+            return;
+        }
+    }
+    sTriedEvolving = 0;
+    gBattleMainFunc = TryEvolvePokemon;
+}
+
 static void TryEvolvePokemon(void)
 {
     s32 i;
@@ -5208,7 +5239,7 @@ static void TryEvolvePokemon(void)
 static void WaitForEvoSceneToFinish(void)
 {
     if (gMain.callback2 == BattleMainCB2)
-        gBattleMainFunc = TryEvolvePokemon;
+        gBattleMainFunc = TrySpecialEvolution;
 }
 
 static void ReturnFromBattleToOverworld(void)
diff --git a/src/battle_script_commands.c b/src/battle_script_commands.c
index d6edb0ab2d..4ae67d1a28 100644
--- a/src/battle_script_commands.c
+++ b/src/battle_script_commands.c
@@ -1914,6 +1914,7 @@ s8 GetInverseCritChance(u8 battlerAtk, u8 battlerDef, u32 move)
 
 static void Cmd_critcalc(void)
 {
+    u16 partySlot;
     s32 critChance = CalcCritChanceStage(gBattlerAttacker, gBattlerTarget, gCurrentMove, TRUE);
     gPotentialItemEffectBattler = gBattlerAttacker;
 
@@ -1928,6 +1929,12 @@ static void Cmd_critcalc(void)
     else
         gIsCriticalHit = FALSE;
 
+    // Counter for EVO_CRITICAL_HITS.
+    partySlot = gBattlerPartyIndexes[gBattlerAttacker];
+    if (gIsCriticalHit && GetBattlerSide(gBattlerAttacker) == B_SIDE_PLAYER
+        && !(gBattleTypeFlags & BATTLE_TYPE_MULTI && GetBattlerPosition(gBattlerAttacker) == B_POSITION_PLAYER_LEFT))
+        gPartyCriticalHits[partySlot]++;
+
     gBattlescriptCurrInstr++;
 }
 
diff --git a/src/pokemon.c b/src/pokemon.c
index 71176d2eb6..ff2dcbe510 100644
--- a/src/pokemon.c
+++ b/src/pokemon.c
@@ -5394,6 +5394,19 @@ u16 GetEvolutionTargetSpecies(struct Pokemon *mon, u8 mode, u16 evolutionItem)
             }
         }
         break;
+    // Battle evolution without leveling; party slot is being passed into the evolutionItem arg.
+    case EVO_MODE_BATTLE_SPECIAL:
+        for (i = 0; i < EVOS_PER_MON; i++)
+        {
+            switch (gEvolutionTable[species][i].method)
+            {
+            case EVO_CRITICAL_HITS:
+                if (gPartyCriticalHits[evolutionItem] >= gEvolutionTable[species][i].param)
+                    targetSpecies = gEvolutionTable[species][i].targetSpecies;
+                break;
+            }
+        }
+        break;
     }
 
     return targetSpecies;