Danny Rose was Mansfield's hero for the second week in a row as he stole an 87th-minute winner in a 2-1 home victory against Sky Bet League Two play-off rivals Cambridge.
Krystian Pearce nodded down a David Mirfin ball into the box and Rose was there to sweep in his second match-winner in successive games.
Mansfield had bagged their first home goal against Cambridge in 444 minutes of football on 65 minutes after George Maris tripped Hayden White, keeper David Forde half-stopping Jacob Mellis' penalty but unable to prevent it trickling over the line.
United had grabbed the lead seven minutes earlier when Leon Legge met Piero Mingoia's corner with a header into the turf and up under the bar.
A very tight first half saw one real chance on 25 minutes as home keeper Conrad Logan was forced down to his left to parry a powerful low Jevani Brown shot from just outside the box after Jabo Ibehre was able to nod down a right-wing cross from Gary Deegan into his path.