Captain Marc Richards scored a goal and then missed a penalty as Vale lost their League Two clash to Oxford United at the Kassam Stadium.
Micky Adams kept faith with the same starting line-up that defeated Bristol Rovers in midweek.
Oxford started the brightest and took the lead after just 10 minutes through central defender Michael Duberry.
In an open game, Vale tried hard to force an equaliser and it eventually came on the hour mark when Marc Richards was on hand to score his fifth goal of the season.
But almost as soon as Vale levelled matters, the home side went in front again. Two minutes after Vale’s goal, Leven scored a superb long-range effort from the half-way line that beat the unfortunate Tomlinson.
Vale threw on Roberts for his first appearance in six weeks with 15 minutes to go. And five minutes later, Richards was brought down in the box by Duberry and Vale were awarded a penalty. Richards took the resulting spot-kick, but Oxford keeper Clarke pulled off a decent save.
In the dying moments, substitute Ben Williamson had a shot cleared off the line as Vale tried in vain to force an equaliser.
Vale: Tomlinson, Yates, Owen, Chilvers, McDonald (Williamson), Taylor, Griffith (Morsy), Loft (Roberts), Rigg, Pope, Richards
Subs: Martin, Dodds