BUENOS AIRES Crowd violence marred Colon's 2-0 home win over Union in the Argentine championship on Sunday as the heated Santa Fe derby was held up for 10 minutes while riot police restored order.
Union fans broke perimeter fencing in a bid to invade the pitch during the match but were held back by riot police using high-pressure water hoses.
Colon's second goal in the 70th minute also sparked anger among the fans. Striker Emanuel Gigliotti scored while team mate Facundo Curuchet was in an offside position judging by television replays.
The top two teams, Velez Sarsfield and Newell's Old Boys, both lost at home, leaving the way open for Lanus to take over the lead if they can secure a seventh successive victory away to Belgrano in Cordoba on Monday.
Velez had the best chances against Boca Juniors but lost 1-0 to a first half goal by Uruguayan striker Santiago "Tank" Silva, who won the Clausura title with them in June 2011.
The home side's leading scorer Facundo Ferreyra failed to add to his tally of six goals in the previous three matches when he missed a sitter and also had a goal disallowed for pushing.
Boca climbed to fourth, five points behind Velez and two short of Lanus and Newell's.
Previously unbeaten Newell's lost 2-1 to modest All Boys after an astonishing faux pas by their goalkeeper Nahuel Guzman.
Guzman tried to play the ball out of his box, lost it to Mauro Matos, chased the striker halfway round the box and brought him down from behind, giving away a penalty which Matos converted to put All Boys two goals up.
"We lost (for the first time) when we least expected it," said Newell's coach Gerardo Martino.
"To win the championship we had to win our remaining four matches and hope the leaders slipped up," he told reporters.
"I'm sure that after Monday's matches there won't be only one leader. If there's another chance we'll try to take it but we have the feeling something's escaped us."
Newell's also lost their three most experienced players - former Argentina internationals Maxi Rodriguez, Gabriel Heinze and Lucas Bernardi - to injury during the match. All three are in danger of missing the last four matches.
The violence at Colon occurred four days after Independiente's home match with Belgrano was suspended when hooligans threw flares onto the Libertadores de America pitch, stunning visiting goalkeeper Juan Carlos Olave.
Troubled Independiente, who are in the relegation zone, lost 2-0 at Estudiantes on Saturday going a fourth match without victory.
Club president Javier Cantero is attempting to rid Independiente of its "barrabravas", or hooligan fans, who enjoyed favours from the previous administration.
The Argentine Football Association is expected to rule that the remaining 45 minutes of Wednesday's suspended match be played behind closed doors.
(Reporting by Rex Gowar; Editing by Peter Rutherford)