League One side Leyton Orient claimed a surprise win at Championship hosts Millwall as Dan Agyei's first-half strike earned them a place in the third round of the Carabao Cup.
In the first meeting between the London teams since 2010, the lively Agyei struck from the edge of the penalty area into the bottom corner following a slick sequence of passing for his second goal in this season's competition.
Much-changed Millwall did not test opposition goalkeeper Zach Hemming as Neil Harris' side, who are winless in the second tier, failed to score for a second consecutive game.
Orient have lost all three of their league matches in 2023-24 but have now progressed beyond the second round of the EFL Cup for only the fourth time in 33 seasons.
Agyei's fine finish early on proved to be the only shot on target from two sides who are struggling for early-season form.
Harris introduced eight new faces to his starting XI from the Lions' 0-0 draw at Hull City in the Championship on Saturday.
It included a debut for Daniel Kelly which made the 18-year-old the first signing from Celtic to represent the club for 65 years.
The midfielder was replaced alongside George Honeyman at the break following a flat first half, Casper De Norre and Romain Esse coming on for the pair in a switch that did little to change the momentum of the contest.
Charlie Kelman hit the side netting for Orient with five minutes remaining and Millwall pushed in vain during the closing stages, suffering their third defeat in five games in all competitions.