The Reds battled hard and true in the Yorkshire derby against a strong, organised and direct Leeds side, and managed to hang on to a point with ten men.
Marcus Tudgay was sent off for a challenge on Zaliukas which saw the hosts throw the kitchen sink at the Reds towards the end, but a point was well earned.
Hassell sent a delightful ball through for Tudgay to flick into the path of Mellis, but the midfielder was denied from a tight angle as Kenny blocked for a corner on two minutes.
On the four-minute mark Smith barged his way into a one-on-one situation with Jack Butland and it seemed a certainty the big striker would find the net. Butland did tremendously well to make himself big and thwart United's striker.
Again Smith had half a chance when he got the better of Ramage on 12 minutes but he could only scuff at Butland from just inside the area.
The hosts were utilising their big, target-man well in Smith and the dangerous McCormack was looking for the nod-down in space as the tempo slowed at the midway point of the first half.
Hassell's delightfully chipped free-kick was met expertly by Tudgay's header on 38 minutes and Kenny had to tip over for a corner.
Barely a minute later Tudgay got in on Kenny after muscling past Lees but he fired wide with the goal at his mercy.
The Fourth Official indicated two minutes' of stoppage time at the end of the half but neither side could find a breakthrough.
Brian McDermott obviously wasn't content with what he saw in the first half and made two changes - Tonge and Byram replacing Mowatt and Peltier.
Cywka saw a shot blocked after Ramage cleared a dangerous cross at the other end moments before.
On 59 minutes a brilliant O'Brien delivery from the right evaded the head of Cywka by inches as the Pole ghosted in at the far post.
Hassell went down with cramp on the hour, which was understandable considering he'd only played 23 minutes all season.
Stephen Dawson replaced Hassell in the middle of the park for the Reds' first substitution. Butland had to react quick to a header from close range and did well to claw the ball away from goal.
Etuhu came on for Cywka with 23 minutes left to play and immediately got involved going forward. After spreading the play to O'Brien on the left, a ricochet eventually fell for Mellis inside the box but he snatched at his chance and hit the side-netting.
The Reds sprang forward on 76 minutes and Perkins' pass split the Leeds defence open for O'Brien but he couldn't direct his left-footed shot past Kenny.
Smith showed his capabilities on the deck when he controlled well under pressure but dragged his effort just wide of Butland's far post.
Danny Wilson's final throw of the dice saw Jason Scotland come on for Jim O'Brien with seven minutes left.
A massive blow was dealt as Marcus Tudgay was given his marching orders for a challenge on Zaliukas with six minutes left.
It was all about hanging on in the final few minutes as Leeds continued to pump the ball up to the gigantic Smith.
A tremendous six minutes of stoppage time was indicated by the Fourth Official.
The Reds might have nicked it three minutes into stoppage time but Mellis saw his effort blocked after Etuhu robbed his man on the right-wing.
Barnsley held on and claimed a valuable point at Elland Road.
Leeds Utd: Kenny, Peltier (Byram 46), Lees, Pearce, Murphy (Poleon 79), Austin, Pugh, Smith, Zaliukas, Mowatt (Tonge 46), McCormack.
Subs: Warnock, Brown, Diouf, Cairns.
Reds: Butland, Tudgay (sent off 84), Wiseman, Ramage, Mellis, Perkins, Hassell (Dawson 63), Cywka (Etuhu 67), Nyatanga, O'Brien (Scotland 83), Cranie.
Subs: M'voto, Pedersen, Kennedy, Fox.
Referee: Keith Stroud
Assistant Referees: Peter Gooch & Danny Markham
Fourth Official: David Richardson