Crawley Town suffered their first home defeat of 2019 when a 27th minute goal by Port Vale's Ricky Miller settled the close battle.
Miller scored the only goal of the game on the rebound from a difficult angle in a game which offered little to warm up the home fans in chilly conditions.
Reds made two changes to the side which lost at Mansfield Town with Dannie Bulman and Panutche Camara replacing the suspended Josh Payne and Luke Gambin, who was on the bench.
New signing Tom Dallison made his home debut in central defence having joined for his second spell at the club in the January window from Falkirk.
Striker Ricardo German, Reds' other new signing, was named on the bench for the first time since signing from non-league club Hendon.
Mark Connolly nearly gave a goal away with a mistake when he passed back to 'keeper Glenn Morris with two opposing players lurking however he combined with Morris to brilliantly clear the danger.
Reds had two good chances to score in quick succession by Filipe Morais and Dominic Poleon which went close.
But the visitors took the lead in the 27th minute when Ricky Miller scored on the rebound from a narrow angle after his first attempt was saved by Morris.
Visiting goalkeeper Scott Brown pulled off a good save to keep out a volley by Morais who then with another chance curled over the bar from 25 yards.
It was a cagey affair in the second half with neither side creating much in the way of clear-cut chances.
Port Vale had an appeal for a penalty ruled out as Morris caught the ball.
Gabriele Cioffi brought on Luke Gambin in place of Poloen as Reds went in search of creative spark in midfield, with Morais pushing forward with Palmer up front.
Reds then brought on Ashley Nathaniel-George for Morais for their second substitution.
He had a go on goal from long range which flew frustratingly over the bar.
Finally Reds' other new signing Ricardo German replaced Morais to make his Crawley Town debut.
The game ended with neither side really threatening to add to the scoreline as Reds suffered their third successive defeat.
Crawley Town: Morris, Young, Connolly, Palmer, Poleon (Gambin 62), Francomb, Maguire, Dallison, Bulman, Morais (capt) (Nathaniel-George 71), Camara
Subs: Mersin, McNerney, German, Sesay
Port Vale: Brown, Gibbons, Joyce, Kay (capt), Oyleke, Miller, Hannant, Rawlinson, Crookes, Smith, Clark
Subs: Hornby, Legge, Pugh, Elliott, Vassell, Conlon, Whitfield
Referee: Dean Whitestone
Attendance: 2,089 (257 away)
Man of the Match: Tom Dallison