Substitute Adam Lallana celebrates his goal for Southampton in the 2-0 win at Reading.
But Gunners defender Per Mertesacker was dismissed in the closing stages for bringing down Albion striker Shane Long.
Tomas Rosicky stoops to head home for Arsenal in the 2-1 win at West Brom.
Tomas Rosicky scored twice to boost Arsenal's Champions League hopes in a 2-1 win at West Bromwich Albion.
The Czech Republic international also headed off the line during an excellent display for the Gunners, who moved above Chelsea into fourth place in the table and just a point behind Tottenham.
However, Arsenal have become a more resilient proposition since their win at Bayern Munich in the Champions League and held on for a crucial victory.
West Brom went close in the opening stages when Rosicky headed a Claudio Yacob effort off the line, but it was Arsenal who broke the deadlock in the 20th minute.
Gervinho was the architect for the Gunners when he cut in from the flank and played the ball into the area, where Rosicky connected at the near post to head home.
Rosicky, who had not scored this season before his opener, added a second five minutes after the interval. The Czech midfielder saw his first effort pushed away by Ben Foster, but Rosicky was able to smash home to make it 2-0 to Arsenal.
However, West Brom hauled themselves back into the game as the Gunners went down to 10 men.
Mertesacker brought down Long inside the area with the Albion striker closing in on goal. The German defender was dismissed, and Morrison made it 2-1 from the penalty spot.
Despite Nigel Adkins' enthusiasm, Reading were beaten 2-0 by Southampton at the Madejski Stadium.
There was to be no revenge for Reading manager Nigel Adkins, as his relegation-threatened side lost 2-0 at home to his former club Southampton at the Madejski Stadium.
The former Saints boss was sacked by the St Mary's Stadium club in January and replaced by Mauricio Pochettino, but Adkins could not prevent his team falling to a seventh successive defeat.
Reading made a bright start to the game, and striker Adam Le Fondre was guilty of a poor miss with only goalkeeper Artur Boruc to beat when he blazed over.
But Reading faded after Jay Rodriguez gave Southampton a 34th-minute lead after linking with Steven Davis.
Southampton substitute Adam Lallana, who had replaced Gaston Ramirez in the 63rd minute, added a second for the visitors with 17 minutes remaining to leave Reading seven points adrift at the foot of the table with just six games left.
A stunning Matt Lowton goal lifted Aston Villa out of the relegation zone in a 3-1 win at Stoke City, which dragged the home side into the thick of the fight to stay in the Premier League.
But Lowton produced a goal-of-the-season contender with his brilliant 35-yard volley three minutes from the end, before Christian Benteke ensured the points returned to Villa Park.
The deserved victory moved Villa three points clear of the drop zone, just a point behind Tony Pulis' team.
Agbonlahor gave Villa the ideal start with his opening strike in the ninth minute of the game. Lowton played a low ball into the area for the striker to connect with. His initial chance was blocked but the ball dropped again for Agbonlahor to give Villa an early lead.
Stoke pulled themselves back into the game with 10 minutes remaining when Kightly struck home after Charlie Adam had played the ball into the area.
However, with three minutes left, Lowton gave Villa the lead with a stunning strike from 35 yards into the top corner.
Benteke then eased Villa out of the bottom three and drew Stoke deep into the relegation mire with his 90th-minute goal.
Luke Moore is congratulated by Swansea teammates after his equaliser against Norwich.
Swansea striker Luke Moore denied Norwich City an important win with his equaliser in the 2-2 draw at Carrow Road.
Michu had given the Swans the lead in the first period before Robert Snodgrass quickly restored parity before half-time.
Michael Turner gave the Canaries a 2-1 lead in the 60th minute, but Moore fired home with 15 minutes remaining to leave Norwich just five points above the relegation zone.
Swansea took the lead in the 36th minute when Jonathan de Guzman cut the ball back from the right for Michu to rifle home the opener for his 17th Premier League goal of the season.
But that lead lasted just four minutes as Norwich hit back. After Nathan Dyer missed a chance at the other end, on-loan Sporting Kansas City forward Kei Kamara chased down the right before finding Elliott Bennett on the overlap.
Bennett crossed into the area and, when Swansea goalkeeper Michel Vorm missed the ball, it dropped for Snodgrass to head home the equaliser.
Swansea were again caught out on the hour mark when a Bennett free-kick found an unmarked Turner at the far post, and he turned the ball home.
However, the home side could not hold on to their vital lead, and Moore slotted home an equaliser from close range following a cross from Angel Rangel.
Norwich substitute Grant Holt was fortunate not to be dismissed after an awful challenge on Chico Flores, which did not even warrant a yellow card from the match official.