Aston Villa boosted their hopes of securing a second consecutive season of Champions League football with victory over already-relegated Southampton – despite Marco Asensio missing two second-half penalties for the visitors.

Ollie Watkins, who had come on for Marcus Rashford midway through the second half, broke the deadlock when he met Youri Tielemans' exquisite pass with a first-time effort which struck the underside of the crossbar on its way in.

Southampton goalkeeper Aaron Ramsdale had denied Asensio from the penalty spot just three minutes earlier, after Watkins had gone to ground under Jan Bednarek's rash challenge.

Donyell Malen, who entered the fray alongside Watkins, made it 2-0 before Ramsdale saved another tame Asensio penalty in added time - only for John McGinn to sweep home the rebound to complete the scoring nine minutes after coming off the bench.

Villa are the first team in Premier League history to have three different substitutes score for them in a single game.

"The subs had a very good impact," Villa boss Unai Emery said. "We were dominating [the first half] but didn't have many chances to score.

"In the second half, the gameplan was the same. We tried to push more and more, and we did. It was a fantastic 90 minutes."

Southampton's Cameron Archer had the best chance of the first half when he shot straight at Emiliano Martinez after running on to Kyle Walker-Peters' pass, but it proved to be Saints' best opening of the match.

The victory lifts Villa up to fifth in the table, while Southampton remain on 10 points.

Reaction to Saturday's Premier League games

Villa face a tall order to overturn their two-goal deficit against PSG on Wednesday, but a run of five victories in their last six league games has left Emery's team well placed to secure an immediate return to the competition next season.

Indeed, since the 1-1 draw with Ipswich in mid-February, the Villans have collected 17 points in the Premier League – more than any other team.

Saturday's game was not the procession some might have predicted before kick-off, as Villa initially struggled to penetrate a deep-lying Southampton side looking to hurt their opponents on the counter-attack.

Rashford had an early header held by Ramsdale, while the Saints keeper also saved two goal-bound shots from Tielemans in a first half lacking in quality.

However, Watkins' second-half introduction proved the turning point as he won Villa's first penalty two minutes after entering the fray, before sending a magnificent finish past Ramsdale to break Southampton's resistance.

Dutch international Malen continued his fine form with a thumping finish from Morgan Rogers' pass, before McGinn – another second-half substitute – spared Asensio's blushes after the PSG loanee's second penalty was parried by Ramsdale.

Asensio is just the fourth player to miss two penalties in a Premier League game after Juan Pablo Angel, Darren Bent and Saido Berahino, but Ramsdale's saves mattered little as Villa moved above fellow Champions League hopefuls Chelsea and Newcastle United.

Saints have now lost 26 of their 32 Premier League games this season, the most defeats across a single league campaign in the club's history.

Their 13 home defeats is also a club record in the top flight, while they have failed to win 11 successive home league matches for only the second time, last doing so in the Championship between October 2008 to February 2009.

Southampton frustrated Villa in the opening quarter of an hour and even threatened to take the lead when Archer stung the palms of Martinez from a tight angle, but they spent the majority of the 90 minutes camped on the edge of their own penalty area against the dominant visitors.

Interim manager Simon Rusk will take heart from his team's display up until Watkins' opener, but once the England international had broken the deadlock there seemed little hope of Saints picking up the point they needed to equal Derby County's all-time tally of 11 from the 2007-08 season.

Villa's late rally also means Southampton have conceded 20 goals in the last 15 minutes of the second half this season – more than any other team in the league.

"I think we have something to build on," Rusk told BBC Match of the Day. "The first goal came in 73rd minute, but we had a clean sheet until then. We were well in the game.

"We were disappointed with the nature of the goal we conceded, but I'm going to take a lot from that game. The players gave their all."