Sutton paid the penalty for a slow start at Vale Park, conceding twice in the first quarter of the game and unable to repeat the comeback from two goals down that had been achieved when the sides met at the VBS in October.
From the point at Port Vale went two up there was little between the sides and U's spurned several opportunities to get back in to the game, with returning captain Craig Eastmond three times failing to hit the target from good positions on the edge of the area, exactly a year after a similar chance had fallen to him with more successful results in the last minute at Halifax.
Eastmond was one of four players who had missed Tuesday's win at Oldham to return to the starting line-up, with Harry Beautyman also beginning the game, while Isaac Olaofe and Will Randall returned to the substitutes' bench, but U's were slow out of the blocks and James Wilson had already hit the side netting when he put Port Vale ahead after six minutes. There was a touch of fortune about the goal, Jamie Proctor collecting Malvind Benning's low cross and miscuing his shot to such an extent that it turned in to a perfect pass for Wilson, who bundled the ball in after his first shot had been blocked at point blank range by Dean Bouzanis, making his 100th appearance for U's.
It wasn't the perfect start for Port Vale, who lost captain Tom Pett to injury five minutes later, but they shrugged off this setback to double their lead in spectacular style. Benning was again the provider, his cross headed out by Louis John but returned in to the roof of the net from the edge of the penalty area by Proctor's superb volley.
There had been signs before that goal of an improvement from U's, and that continued for the rest of the first half. Eastmond was only just wide with a half volley from the edge of the area following a penalty area scramble, but later in the half skied an effort from a similar position high over the bar.
The home side could have put U's out of the game early in the second half when, following more good work by Benning, centre back Connor Hall shot over when he should have done better. As it was, Sutton enjoyed a good spell and when goalkeeper Aidan Stone dropped Joe Kizzi's cross under little pressure, Omar Bugiel was unable to keep his shot on the turn down, Nathan Smith doing just enough to put him off. Eastmond's third opportunity came soon afterwards, this time his sidefooted effort from the edge of the penalty area sliced wide, and having survived those scares Port Vale came close again when Harry Charsley capitalised on a slip by David Ajiboye to set up Proctor but this time Bouzanis made a good save.
U's brought on Olaofe for Donovan Wilson with just under half an hour to go, but it was a Port Vale substitute, David Amoo, who had a more immediate impact, pouncing on a poor touch from John and forcing a foul out of the defender which earned a booking. Soon afterwards Proctor was booked for a foul on Eastmond, and from Beautyman's free kick Kizzi's superb header came back off the angle of post and bar and was cleared to safety.
That was the closest U's came to giving Port Vale an anxious last few minutes, and Hall missed another chance from inside the penalty area before the end as the home side moved up to fourth in what is still a very congested promotion picture, just five points separating Northampton in third and Sutton in tenth.
Sutton: D Bouzanis, J Kizzi, B Wyatt, C Eastmond, B Goodliffe, L John, D Ajiboye(sub W Randall 65), D Wilson(sub I Olaofe 62 ), O Bugiel(sub R Bennett 76), H Beautyman, E Boldewijn. Subs n/u S Nelson, C Rowe, K Davis, R Korboa. Booked: John
Port Vale: A Stone, T Pett(sub A Martin 12), H Charsley, B Walker, C Hall, N Smith, D Worrall(sub S Robinson 87), B Garrity, J Wilson(sub D Amoo 65), J Proctor, M Benning. Subs n/u T Holy, A Hurst, R Edmondson, K Harratt. Booked: Walker, Proctor.
Referee: Martin Coy
Attendance: 6,362(132 away)