Arsenal's push for a place in the Champions League for a 16th successive season continued on Saturday when two Tomas Rosicky goals gave them a 2-1 win at West Bromwich Albion and lifted them to fourth in the Premier League table.
Aston Villa eased their relegation worries by winning 3-1 at Stoke City and Southampton virtually guaranteed their safety with a 2-0 victory at Reading who look doomed.
The day's other match between Norwich City and Swansea City ended in a 2-2 draw at Carrow Road.
Arsenal claimed their sixth win in seven league games despite having German centre back Per Mertesacker sent off 19 minutes from time for a foul on Albion striker Shane Long.
James Morrison scored from the resulting penalty but Arsenal hung on for the three points that took them on to 56 points from 31 matches, one behind arch-rivals Tottenham Hotspur who are third on 57, also from 31 games. They are one ahead of Chelsea who slipped back to fifth on 55 points from 30 games.
Spurs are at home to Everton and Chelsea host Sunderland on Sunday, but even if they both win and Arsenal finish the weekend back in fifth place, the Gunners have served notice of their intent after being outside the top four since before Christmas.
The race for third and fourth places looks to be between the three London rivals with Manchester United and Manchester City, who meet at Old Trafford on Monday, looking set to finish first and second.
Rosicky, who only started his first Premier League match of the season last week after months disrupted by injury, headed Arsenal in front after 20 minutes and scored from a rebound in the 50th minute.
Mertesacker was shown his red card by referee Howard Webb for tripping Long and after Morrison scored from the spot, Albion went close to an equaliser several times.
"Tomas Rosicky has been out for six months but showed his quality today and why he is so important to us," manager Arsene Wenger told Sky Sports.
"We know if we win all our games no-one can stop us, but it was a very nervy last 20 minutes. If you make a single mistake in the box it can cost you, but we kept our nerve."
Southampton dented the survival hopes of their former manager Nigel Adkins and his Reading team when they beat them 2-0 in a lunchtime kickoff.
Goals from Jay Rodriguez and Adam Lallana sealed Southampton's victory which lifted them to 11th. Reading stayed bottom of the table, level on 23 points with Queens Park Rangers, who host Wigan Athletic on Sunday.
Aston Villa moved out of the relegation zone and improved their chances of staying up with a good win at Stoke, who are sliding towards trouble with just one victory in 13 league games.
Villa manager Paul Lambert told the BBC: "It was thoroughly deserved. We looked terrific from the off.
"I thought we defended really strongly and football-wise I thought we were excellent. Every time we went forward I thought we looked threatening."
He also praised young fullback Matt Lowton for a stunning goal that sealed the points.
"I don't think you will see a better goal in Europe let alone anywhere else than Matt Lowton's.
"The technique, chest control and volley was outstanding. He has played every minute of every game in the league and he has been outstanding."
Norwich seem to be consolidating their place in the Premier League and can look forward to a third season in the top flight after a draw with Swansea.
The Canaries survived an injury to goalkeeper Mark Bunn in the first half and were winning with goals from Michael Turner and Robert Snodgrass until Like Moore equalised 15 minutes from time. Michu had put Swansea ahead in the 35th minute with his 21st goal of the season.