Next day, the RFC found itself fighting in the Battle of Mons and two days after that, gained its first air victory. On 25 August, Lt C. W. Wilson and Lt C. E. C. Rabagliati forced down a German Etrich Taube, which had approached their aerodrome while they were refuelling their Avro 504. Another RFC machine landed nearby and the RFC observer chased the German pilot into nearby woods. After the Great Retreat from Mons, the Corps fell back to the Marne where in September, the RFC again proved its value by identifying von Kluck's First Army's left wheel against the exposed French flank. This information was significant as the First Army's manoeuvre allowed French forces to make an effective counter-attack at the Battle of the Marne.