Which 1810 battle stopped Masséna before the Lines of Torres Vedras?

The 1810 battle that stopped Masséna before the Lines of Torres Vedras was the Battle of Bussaco.

The battle was fought on 27 September 1810 in Portugal during the Peninsular War. Marshal André Masséna was leading a French invasion intended to drive Wellington’s Anglo-Portuguese army out of Portugal and capture Lisbon. Wellington positioned his troops along the steep ridge of Bussaco, using the terrain to strengthen the defensive line.

French attacks pushed up difficult slopes in several columns, but British and Portuguese troops held the ridge and inflicted heavy losses. The French won no decisive breakthrough and continued their advance only after Wellington withdrew toward the fortified Lines of Torres Vedras. Thus Bussaco delayed Masséna long enough for the defensive works around Lisbon to be completed.

The battle did not itself destroy Masséna’s army or permanently halt its movement. French forces reached the lines in October, but found an extensive defensive system supported by scorched-earth measures that denied food and fodder. Unable to force or sustain an assault, Masséna eventually retreated in November. Bussaco is therefore best understood as the delaying victory that protected the unfinished defenses.