AMSTERDAM, April 13 (Reuters) - PSV Eindhoven had to cancel their Dutch championship celebrations for a week when they were held to a 1-1 draw by Twente Enschede on Sunday.
Second-placed Ajax Amsterdam's match at Groningen was postponed after paper thrown on to the pitch by the home crowd caught fire and caused an evacuation of part of the stands.
Blaise N'Kufo put Twente ahead in Eindhoven 10 minutes before the interval but midway through the second half Jefferson Farfan equalised with a shot from 18 metres following an impressive run past two opponents.
Twente defender Luke Wilkshire received his second booking and was sent off in injury time.
With one match remaining, PSV are top with 69 points, six above Ajax who have a game in hand. PSV will travel Vitesse Arnhem next weekend and Ajax will host Heracles Almelo.
NAC Breda are third with 63 points following their 1-0 win at Heracles, Edwin de Graaf scoring in the 59th minute. NAC are now guaranteed a place in the playoffs of teams from second to fifth for a Champions League third qualifying round ticket.
Twente are fourth with 59 points, two more then Heerenveen and Feyenoord, who lost at Sparta Rotterdam and Willem II Tilburg respectively.
Sparta staged a remarkable comeback, scoring four second half goals to fight back from 2-0 down at halftime.
Danijel Pranjic and Gerald Sibon gave Heerenveen a comfortable lead but Charles Dissels, Nourdin Boukhari, Sjaak Polak and Marvin Emnes turned the tide for Sparta who are now safe from relegation.
Frank Demouge struck twice to inspire Willem II to a 3-1 victory over Feyenoord, with Said Boutahar adding a third before Andre Bahia replied.
At the bottom, Excelsior Rotterdam leapfrogged VVV Venlo after a 1-1 home draw against AZ Alkmaar, while VVV suffered a 4-1 defeat at neighbours Roda JC Kerkrade.
VVV slipped to 18th with 26 points, one behind Excelsior.