There are limited options for preventing damage from overfertilizing a lawn. The good news is the best fix is a simple one. Washing the fertilizer through the lawn deep into the soil with water is the solution and can often prevent permanent damage. A result of excess fertilizer and drench watering will be fast blade growth, which means that increased mowing will likely be required for a month or so.
Water the lawn immediately after you discover that an excess of fertilizer has been applied. Water slowly and deeply over at least 30 minutes to wash the fertilizer off of the blades to prevent the most immediately visible signs of burn and preserve the green of the grass. Be sure to soak the entire area including the edges to wash out the fertilizer evenly.
Water the lawn again in two to three days and then twice per week the following week with at least two inches of water, 1 inch at each session. Always water deeply and slowly to percolate the fertilizer down into the soil as opposed to creating chemical runoff that occurs with heavy watering over a short period of time.
Wait to mow the lawn two weeks after the fertilizer mishap. Mowing immediately after can expose the blades and fertilizer, creating burn spots. Mow only dry grass, and remove only one-third of the blade height with each mowing session to reduce stress. Remove more blade height by lowering the cutting blade with successive mowing sessions.