Hull and Swansea earned valuable victories in their battle for English Premier League survival but Middlesbrough slid further towards the drop after a 4-0 hammering at Bournemouth.
Hull's 2-0 win over Stoke City and Swansea's identical scoreline against Watford on Saturday increased the pressure on Crystal Palace and Burnley, who are hovering above the relegation zone and play Liverpool and Manchester United respectively on Sunday.
With four games remaining, 17th-placed Hull are one place above the drop zone with 33 points to the 31 of Swansea.
Boro are in 19th spot on 24 points and Sunderland are bottom on 21.
Hull had a tough task after Oumar Niasse was surprisingly shown a straight red card after 25 minutes for a challenge on M'Baye Niang.
But the Tigers took the lead just past the hour when Liverpool loanee Lazar Markovic scored from close range after his header had bounced down on the goal line.
Hull made sure of the points nine minutes later when Sam Clucas found the top corner with superb 30-metre shot. They have now won four consecutive home league games. "I'm really happy. It was not easy. We played with 10 players, but our boys were fantastic and they deserved it," Hull manager Marco Silva told the BBC.
"I'm really happy but we still have four games to fight. Maybe in January no one would believe in our club to survive."
Spanish striker Fernando Llorente gave Swansea the lead with a trademark header from a corner in the 10th minute and the Welsh side were given a break when Marko Arnautovic missed a second-half penalty.
Swansea made sure of the win when Tom Carroll's shot found the top corner via a deflection off Joe Allen.
Time is running out for Boro who have not won in 16 league games and they endured a nightmare opening 20 minutes in which they conceded two goals and had midfielder Gaston Ramirez sent off for a second booking.
Josh King scored just 96 seconds into the match and Benik Afobe doubled the advantage for the Cherries.
Winger Marc Push made it 3-0 and Charlie Daniels completed the rout.
In Saturday's fourth clash, West Ham and Everton played out a dour goalless draw at the London Stadium, delivering a severe blow to the Toffees' hopes of an already unlikely top-six finish.