Walsall were knocked off the top of League Two as Oldham snatched a 2-1 victory in the dying seconds, ending the hosts' eight-match unbeaten run in the process.
After Joe Garner's first-half header had put the visitors ahead, Daniel Kanu hauled Walsall level early in the second period, only for a stoppage-time corner to break Saddlers hearts at the death.
A Lively Opening at the Bescot
The Saddlers almost made a dream start after 75 seconds when Evan Weir's half-volley looked destined for the bottom right corner, only for Latics goalkeeper Mathew Hudson to deny him with a fine save.