Mason Warren coolly curled home the only goal of the game as Boston United booked their place in the semi-finals of the Lincolnshire Senior Cup.
With 59 minutes gone the winger collected Harry Vince’s pass on the edge of the Lincoln United penalty area, set himself and bent an effort beyond the dive of Jake Turner.
It was the only goal of the game at Ashby Avenue, a contest which went ahead despite a heavy downpour prior to kick off.
But it was enough to ensure Boston will now face the winners of Thursday’s contest between Grimsby Town and Scunthorpe United.
Adam Murray named three Rotherham United players in his squad.
Kuda Muskwe, Darnelle Bailey-King and Warren are all training with the club with an eye on loan stints at the Jakemans Stadium.
After the heavy rain cleared the skippy surface saw both teams take their time to get footholds in the game in a first half of few chances.
Boston’s Tyrell Waite brought a good save from Turner following some direct running, while the Whites keeper also held onto Adam Chapman’s snapshot.
After the interval Conner Robinson - one of a number of ex-Pilgrims in the home side’s ranks - curled a free kick over George Willis’ bar.
Warren then had his say on the contest, finding the net before being instantly replaced by Bailey-King.
Liam Adams came close to doubling the advantage when his audacious effort from distance whizzed wide of the post.
WHITES: Turner, Millard, Anderson, Toyne (Brooks 69), Ward, Wright, Fairclough (Wilkinson 86), Norris (Hall 67), Wightwick (Cann 67), Robinson, Smith; Sub (not used): Oliver.
UNITED: Willis, Hare (Clifton HT), Cowgill, Keane, Beatson (Batchelor 67), Hemmings (Vince HT), Chapman (Adams 67), Broadhead, Warren (Bailey-King 60), Tshimanga (Muskwe HT), Waite (Yeomans 67).
Ref: David Jones.