Twente beat NEC to close gap on PSV
PSV suffered a shock 4-2 loss at mid-table NAC Breda on Friday to remain on 34 points from 16 matches and now lead Twente only on goal difference.
Bas Sibum had put NEC ahead after nine minutes but Ruiz equalised with a volley before Janko struck from close range after being set up by Nacer Chadli shortly before the break.
Ruiz's penalty on the stroke of half-time made it 3-1 but he was carried off on a stretcher 10 minutes from time following Janko's second goal after Bjorn Vleminckx pulled one back.
Third-placed Groningen failed to close in on the leaders as they lost 1-0 at Roda JC Kerkrade. Arnaud Sutchuin Djoum settled the match five minutes before the interval.
AZ Alkmaar, who are fourth, dropped points in a 2-2 home draw against Heerenveen with Kolbeinn Sigthorsson on target in the final minutes to salvage a share of the spoils for Alkmaar.
Bottom side Willem II Tilburg got only their third point of the season when Evgeniy Levchenko's accurate shot from 15 metres a minute from time salvaged a 1-1 draw with Excelsior Rotterdam.