Cheltenham dented Cambridge's automatic promotion hopes with a last-gasp equaliser at the EV Charger Points Stadium, snatching a 1-1 draw deep into added time.
Sullay Kaikai had given the visitors a 34th-minute lead, but Luke Young's cross was deflected into his own net by Jake Eastwood in the first minute of stoppage time to level the match.
Kaikai Pounces in a Subdued First Half
United took the lead when Kaikai lashed in a shot from the centre of the box in the 34th minute, after Mamadou Jobe nodded a cross to him at the far post.