Panathinaikos closed the gap on Olympiakos to one point again following a 3-1 win over Atromitos in a disrupted game at the Olympic Stadium on Sunday.

The game was held up for half an hour in the second half, when PAO were 2-1 up after riots that broke out in central Athens following protests to mark the one-year anniversary of the shooting of a teenager by a policeman spread to the Olympic Stadium.

Dozens of people clashed with police outside the ground, causing officers to fire tear gas, which was blown into the stadium and forced the referee to halt play while the atmosphere cleared.

Earlier, Panathinaikos had started like a side determined to make up for last week’s defeat against Olympiakos.

Costas Katsouranis opened the scoring in just the sixth minute. The Greece midfielder added a second, and his eighth of the season, in the 33rd minute as the Greens looked to be on their way to a comfortable win.

But Atromitos struck back in first half stoppage time when Paschalis Melissas was left unmarked at a corner to head home.

Both teams looked out of sorts following the delay in the second half and it was not until the first minute of injury time that the final result was settled as Djibril Cisse fired home, making up for hitting the post when the score was 2-0.

The win means that Panathinaikos move to 32 points after 13 games with Olympiakos on 33.

The score was also 3-1 in Nea Smyrni, where Panionios beat AEK. The home side took the lead in the 21st minute through Yiannis Maniatis but the Yellows struck back seven minutes later through Leonardo.

However, Panionios proved too strong for struggling AEK in the second half and late goals from Sito Riera and Bosko Balaban sealed a memorable win and to move into joint-fourth place.

Iraklis also scored three goals to beat PAS Yiannina 3-2 away from home. Second-half goals from Dennis Epstein and Panayiotis Kone came after impressive counter-attacks from the Thessaloniki side, who seem a different proposition under the management of Savvas Kofidis and are now climbing away from the relegation zone and towards mid-table security.

Also on Sunday, Ergotelis moved above Kavala into fifth place after beating the visitors to Crete 1-0 and are also in fourth on 21 points.

Panthrakikos doubled their points with a 0-0 home draw against Asteras Tripolis.

On Saturday Olympiakos took on 11th placed Xanthi but returning to Piraeus with all three points was no easy task.

Olympiakos took the lead in the 31st minute when in-form Costas  Mitroglou just managed to keep himself onside and then produced some nifty footwork inside the area to make room to produce an inviting cross that Leonardo, who had scampered into the box from his left-back position, poked in to the net after sliding in past his marker.

A couple of minutes earlier, Antonis Nikopolidis had to make a smart save after a Xanthi corner led to a deflection which almost wrongfooted the goalkeeper.

The second half saw the visitors play mostly on the counter attack as Xanthi turned up the pressure but without really threatening Nikopolidis.

Luciano Galletti had the chance to wrap things up in the second minute of injury time but shot tamely with his right foot. But the referee blew just seconds later to the relief of Zico’s players.

In Thessaloniki, PAOK took the lead in just the fourth minute through a penalty by Vladan Ivic. The visitors’ task was made more difficult in the 54th minute when Angel Gaston Casas was sent off after receiving a straight red card.

Larissa coach Marinos Ouzounidis used all three of his substitutions in the second half in an attempt to find an equaliser but PAOK held on the win, which puts them on 24 points from 13 games – six points clear of Kavala who play on Sunday.

Hector Raul Cuper saw Aris pick up their first win since he took over last month, with a straightforward 2-0 victory at Levadiakos.

Javier Campora opened the scoring for the visitors in the 41st minute. Levadiakos had a good penalty shout in the second half before former Birmingham City midfielder Mehdi Nafti secured all three points in the 78th minute.

The win leaves Aris mid-table and Levadiakos stuck in the relegation zone.