Leicester remain firmly on course for promotion to the Premier League after a 3-0 win over Ipswich, while second placed Burnley also look well placed to reach the top-flight.
Nigel Pearson's Foxes are eight points clear at the top of the Championship, and unbeaten in 13 league matches thanks to goals from Jamie Vardy, David Nugent and Chris Wood at the King Power Stadium.
Vardy struck for his 12th goal of the season in the 19th minute and Nugent tapped home for his 18th on the half-hour mark, while substitute Wood netted in the 88th minute.
"I know Nugent was looking forward to playing against Ipswich but I don't suppose they were too keen (to face him)," Pearson said.
"It was a good result and good all-round performance against a decent side."
Burnley kept hold of the second automatic promotion berth, easing to a 3-1 victory over Nottingham Forest at Turf Moor.
Fifth placed Forest started the day just five points behind Burnley, but Sean Dyche's side were too strong for the visitors.
After Scott Arfield opened the scoring for the Clarets in the 12th minute, Vokes followed up with two goals in 10 minutes as the hosts went into the break well in charge.
Djamel Abdoun hit back for Forest towards the end, tapping in after seeing his penalty saved, but Billy Davies' team could not mount a late fightback.
Third placed Derby are also in the hunt for automatic promotion and they stayed two points behind Burnley after a hard-fought 1-0 win over Bournemouth.
The visitors were the better side in the first half at the iPro Stadium, but wasted several chances after Matt Ritchie hit a post and Derby made them pay when Chris Martin grabbed his 18th goal of the season five minutes from time.
Martin curled a 20-yard free-kick into the top corner to clinch the points and set up a huge clash with Burnley next weekend.
"They had kind of missed their chance and we knew that and knew we would have ours. We were waiting for that one moment of quality and in the end we got it," Derby boss Steve McClaren said.
QPR's hopes of earning a top-two spot suffered a major blow with a 1-0 defeat at struggling Charlton.
The winning goal came in stoppage-time when Charlton captain Johnnie Jackson nodded in an Astrit Ajdarevic corner from a tight angle to secure the Addicks' first league win since Boxing Day.
Harry Redknapp's QPR, the pre-season promotion favourites, have now lost three consecutive matches and lie seven points adrift of Burnley.
Redknapp's assistant manager Kevin Bond insists QPR can't afford to worry about how their promotion rivals were doing.
"All we can do now is get back on track against Leeds. Get back to where we were earlier in season," Bond said.
"As soon as we start looking at bigger picture and promotion then we could be in trouble. We need to focus on next game and getting a point."
Sixth placed Reading's inconsistency returned to haunt them as they lost 1-0 at home to Blackburn.
Elsewhere, bottom of the table Yeovil boosted their survival bid with a 1-0 win over fellow strugglers Doncaster.
Yeovil are three points behind fourth bottom Millwall, who slumped to a 1-0 loss at relegation rivals Barnsley, who are now only two points from safety.
Wigan won 2-1 at Brighton, Bolton beat Watford 2-0 and Birmingham won 2-1 at Blackpool.
Sheffield Wednesday beat local rivals Huddersfield 2-0, while Middlesbrough drew 0-0 with Leeds.