Balchen suffered his first defeat on 10 October 1707. Leaving the safety of Portsmouth harbour, his convoy was ambushed by a French squadron under Forbin and Duguay-Trouin, in what became the Battle at the Lizard. Although the dozen French warships were larger and stronger than the convoy escorts, Balchen took his ship into battle with the other warship captains. This action allowed the merchant convoy time to disperse and escape. The ensuing battle was one-sided, with the French warships battering three English ships into submission over several hours, including Balchen's command, which had been boarded by three French ships of the line. One British warship escaped, but HMS "Devonshire" exploded with the loss of nearly 900 lives. The French captured just 15 merchant ships from the hundreds in the convoy, as most made English ports before their pursuers could catch them.