Rotherham United extended their unbeaten run to 11 matches as they beat the team one place above them in the table to underline their League One promotion credentials.
The fifth-placed Millers travelled to Scunthorpe United and won 2-1 - the third time in their last four matches they have beaten a play-off rival.
Goals from Joe Newell and Semi Ajayi did the damage, securing a fourth straight victory and an eighth in the last 11 games. Rotherham, roared on by a sold-out 2,100 away following, have now scored in 24 consecutive matches and are just a point behind the Iron with a game in hand.
This was a contest between two of the best teams in the division who were prepared to have a go at each other.
Rotherham had shaded the early exchanges and took the lead in the 31st minute when a long throw from Will Vaulks fell for Joe Newell to hook home.
But, leading up to the break, they had to withstand pressure from the home side who had a big 40th-minute shout for a penalty turned down when Marek Rodak parried Funso Ojo's shot and, in his attempt to gather the loose ball, appeared to fell Ivan Toney.
Paul Warne's team went further after 70 minutes when Semi Ajayi headed in, but Scunthorpe hit back just three minutes later through substitute Lee Novak to set up a tense finish.
The Millers saw out the match and could have added to their lead in time added on when sub Caolan Lavery was denied from close in, although they were glad to see Duane Holmes put a last-second chance wide for Scunthorpe.
Scunthorpe United (4-4-2): Gilks; Vermijl, McArdle, Wallace, Townsend (Williams 86); Holmes, Bishop (Adelakun 75), Ojo, Morris; Toney, Hopper (Novak 66). Subs not used: Watson, Goode, Burgess, Yates.
Rotherham United (4-4-2: Rodak; Emmanuel, Ajayi, Wood, Mattock; Forde, Towell, Vaulks, Newell (Williams 69); Smith, Ball (Lavery 75). Subs not used: Price, Palmer, Taylor, Ihiekwe, Yates.
Goals: Novak 73 (Scunthorpe); Newell 31, Ajayi 70 (Rotherham).
Referee: Graham Salisbury (Lancashire).
Attendance: 6,359 (2,100).