Substitute Alexandros Kyziridis' dramatic injury-time winner secured Hearts three points against Livingston to nudge them top of the Scottish Premiership.

Lewis Smith gave Livi the advantage after 26 minutes when he skipped past Harry Milne on the right before cutting inside and sending a low shot beyond Zander Clark at the Hearts goalkeeper's near post.

Claudio Braga had gone closest when his low shot from the right zipped past the far post, but Hearts failed to create anything else for the remainder of the half and appeared to struggle under Livingston's pressure.

But the forward drew the Edinburgh side level in the opening minutes of the second period. Half-time substitute Kyziridis won the corner for his side and then teed up Braga to head beyond Jerome Prior at his near post.

It looked as though a switch had flicked for Hearts at the break and they applied serious pressure on the Livingston backline.

There was a debut for record signing Ageu, who joined from Santa Clara earlier this week, and the midfielder looked sharp with a few chances, going close from just outside the Livi box as he leathered his strike wide.

And the Brazilian almost set up Hearts' second. There was a tangle between the midfielder and Prior inside the Livi box and the ball fell sweetly for Braga with the goal gaping but the forward was denied by the upright.

It was Kyziridis who was the hero for Hearts when, deep into injury time, he raced through on goal and sent his low strike beyond Prior to snatch all three points and open his account for the Edinburgh club.

When the half-time whistle blew it was fair to say Livingston were good value for their 1-0 lead.

Yet again, it was an underwhelming first 45 from McInnes' side who, apart from that early Braga chance, offered very little.

Livingston looked strong going forward and put serious pressure on the Hearts backline for most of the first 45 minutes. Goalscorer Smith caused all sorts of problems and they created a fair few chances.

But, like at Tynecastle against Motherwell last week, it was a different side who came out the traps for the second half.

McInnes' decision to bring on Kyziridis at the break proved inspired when the winger set up Braga for the first, and got on the scoresheet himself, for the second. But just how sustainable is Hearts' reliance on their second-half form?

The schedule is going to get busier and there will likely be games in which they simply cannot afford to leave it until the second half to get themselves into the game.

Livingston manager David Martindale: "It's always difficult to lose late goals. We don't start the second half well.

"I don't think there was much in the first half. I don't think we caused too much trouble offensively, I think we gave Hearts too much possession, maybe too much respect in the second half."

Hearts manager Derek McInnes: "We set up to nullify Livingston's threat but one shot on goal and they scored. It was too simplistic that goal against us.

"We started the second half like an absolute train and we never really let up. The game became stop start, I got fed up hearing the referee's whistle it seemed like every tackle was a foul."

Both sides are in action on Saturday 13 September in the Premiership. Hearts are away to Rangers (15:00 BST), while Livingston travel to Aberdeen.