Acrobatic Strike( Player's Handbook II, p. 71)
[Fighter Bonus Feat, General]
Your dexterous maneuvers and skilled acrobatics allow you to slip past a foe's defenses and deliver an accurate strike against him.
Tumble 12 ranks,
If you succeed in using Tumble to avoid an opponent's attack of opportunity, you gain a +4 bonus on the next attack that you make against that foe as long as the attack occurs before the end of your current turn.
A fighter can select Acrobatic Strike as one of his fighter bonus feats.