According to the first search result, to complete a marathon in 2 hours, you would need to keep the pace of 4 minutes and 34 seconds per mile. The same result also states that the average pace required to complete a marathon in 4 hours is around 9 minutes per mile. However, it is important to note that these are just average paces and can vary depending on factors such as age, gender, fitness level, and terrain.

Additionally, the third search result provides more specific information on the pace required to run a 2-hour marathon. According to the study published in the Journal of Applied Physiology, a runner would need to maintain a pace of 4 minutes and 34.6 seconds per mile, or 13.1 miles per hour, to complete a marathon in 2 hours.