The Spanish number 10 produced an outstanding attacking performance and showed some clever touches as well as taking his goals well as United opened their home account in fine style, admittedly against lower division opposition.
Despite fielding a team showing nine changes from the one that started at Bolton on Sunday, United soon settled into playing some neat football and offered the first threat as Stuart Dallas tested keeper Robert Lainton with a shot from 25 yards out.
Port Vale had their first effort when a quick break saw Rekeil Pyke shoot from the left corner of the box, but his effort was easily dealt with by home keeper Felix Wiedwald.
Leeds went ahead on 12 minutes after Dallas’s cross looked harmless, but was misjudged by Lainton. The ball came back off the post to Saiz and he marked his promising debut with a goal, taking a touch before shooting in off the same post.
It all looked comfortable for the Whites at this stage with Saiz looking sharp in the number 10 role and Dallas offering a threat down the left along with full-back Cameron Borthwick-Jackson who got forward well on his debut following his loan move from Manchester United.
Borthwick-Jackson brought a save out of Lainton with a strike from 20 yards while Dallas hit a shot well over from the edge of the box.
Vurnon Anita, playing at right-back, got forward to shoot wide from the edge of the area, but Vale equalised when a long throw was not dealt with and ex-Leeds player Michael Tonge sneaked in at the back post to score from close range.
The second half, however, was one-way traffic with Vale unable to cope with a home team who upped the pace.
Ronaldo Vieira ran the show in midfield and showed intent with a 25-yarder that went over. New striker Caleb Ekuban, who was quiet in the first half, showed his ability as he chested the ball down on the edge of the box and got in a shot that was saved by Vale’s substitute goalkeeper, Sam Hornby.
The keeper saved comfortably from a Mateusz Klich shot from distance before Leeds boss Thomas Christiansen turned to his bench to put on Ezgjan Alioski and Liam Bridcutt.
A Borthwick-Jackson header from a corner was cleared off the line then Leeds finally had their second goal when Saiz ran onto a superb through ball by Vieira and quick as a flash rounded the keeper to score his second goal.
Within two minutes Saiz was on target again with a powerful strike after latching onto another ball played into the box.
Leeds were on fire now and Dallas fired a half-volley over after getting onto the end of an ambitious Alioski cross.
Alioski, who took his chance to impress on the right wing, hit an angled shot over then saw another effort deflected over.
It was becoming the Alioski show for a spell as he saw a great strike well tipped over by Hornby.
A great run from Alioski led to a fourth goal for the Whites when he got to the edge of the box and pulled the ball back. Saiz cleverly dummied and Ekuban supplied a smart finish for his first goal for the club.
It could have been more late on as Saiz and Bridcutt both hit shots over while a frustrated Vale side ended with 10 men after Gavin Gunning took exception to a bit of skill from Alioski and lashed out to earn himself a second yellow card.
Leeds head coach Christiansen was understandably pleased with the display and result.
He said: “It was important to see the players who didn’t have a chance to play against Bolton.
“It was a good win and we created many opportunities.
“In the first half it was not good enough. We let them play their game a bit and were a bit too deep. But in the second half we got a little bit more speed in the game.
“There’s several players who put their case, but obviously three goals from Samu showed a little bit of what he can do. There’s more to come.
“He’s a player who enjoys having the ball. He has the quality, is intelligent and has good finishing. I’m very pleased with his performance.
“Alioski put more speed in the game and Liam (Bridcutt) did well also.”
Leeds United 4
(Saiz 12, 61, 63, Ekuban 83)
Port Vale 1
Wednesday, August 9, 2017
Carabao Cup, round one
Leeds: Wiedwald, Anita, Ayling (Gomes 70), Shaughnessy, Borthwick-Jackson, Sacko (Alioski 57), Vieira, Klich (Bridcutt 57), Saiz, Dallas, Ekuban.
Port Vale: Lainton (Hornby 45), Davis, Kay, Smith, Gunning (sent-off 87), Turner, Pugh (Harness 80), Reeves, Tonge, Pyke, Forrester (Pope 62).
Referee: Peter Bankes.