Janko hits four in Twente rout
The Austrian forward struck after four minutes to hand Twente an early lead and after Luuk de Jong doubled the score, Janko settled the match on the stroke of half-time with a tight-angled header.
After the break, Janko added two more goals to increase his tally to 12 league goals this season.
The victory put Twente on 40 points from 19 games, one point behind PSV and two ahead of Ajax Amsterdam, who climbed to third thanks to a 2-0 home win over arch rivals Feyenoord.
Toby Alderweireld opened the scoring for Ajax after 31 minutes and Miralem Sulejmani converted a penalty 13 minutes from time in a one-sided match against a toothless Feyenoord, who are 13th in the 18-team league.
AZ Alkmaar remain fifth with 33 points following a 2-2 draw at home to NEC Nijmegen who had Bjorn Vleminckx twice on target as the league's leading goal scorer reached 15 goals.
Utrecht's Atilla Yildirim made his debut and struck from close range in the final minute to earn his team a 2-1 win at lowly VVV Venlo.