David Luiz believes Chelsea must win all five of their remaining English Premier League games to be certain of a place in the Champions League next season.

The Brazil defender’s last-gasp free-kick earned the Blues a 2-1 first-leg advantage in their Europa League semi-final with Switzerland’s Basel on Thursday.

Now attention turns to Swansea on Sunday and the pursuit of a top-four place.

Chelsea could be fifth by kick-off as Tottenham play on Saturday and – although the May 8 clash with Spurs could prove decisive – Luiz reckons Rafael Benitez’s men cannot afford to err in their pursuit of a return to the Champions League they won in 2012.

“We need to take three points in all the games,” Luiz said.

“Tottenham is one key game but we need to keep focused for the future, now on Sunday against Swansea, because they have a very, very good team.

“You saw that in the semi-final of the Capital One Cup. We need to be focused for Sunday.”

The Europa League is Chelsea’s third semi-final of the season. In the first, Swansea overcame the odds to beat the European champions and go on to lift the Capital One Cup.

The bid to avenge that tie is one of the intriguing sub-plots of Sunday’s match.

Eden Hazard was dismissed and suspended for kicking a ball boy at the Liberty Stadium, while Michael Laudrup’s stock is such that it is conceivable he could be a future Chelsea manager.

There is also the matter of Mark Clattenburg refereeing Chelsea for the first time since last autumn’s racism row involving John Obi Mikel, when the official was accused of using “inappropriate language” but later cleared by the Football Association.

That incident is now in the past as Chelsea look to the future following Thursday night’s 2-1 win at Basel.

The Blues took a 12th-minute lead through Victor Moses and spurned numerous opportunities to double their advantage before a soft penalty saw the Swiss champions level with three minutes to go.

Luiz, who was fortunate to only be booked for a poor challenge on Philipp Degen late in the game, then struck, directing his 20-yard free-kick around the wall and inside the post to inflict Basel’s first home loss in seven Europa League games.

“I’m happy with this, if I can help my team with the last kick (of the game),” Luiz said.

“It was a very good game for us, unlucky because we didn’t score more goals, but we have the advantage now in the tie.”

After defeats in the two prior semi-finals this term, Luiz is taking nothing for granted with a place in the May 15 final in Amsterdam at stake as Chelsea bid to become the first team to hold the Europa League and Champions League trophies at the same time, for a period of 10 days.

Although they are playing in their maiden European semi-final, Basel have proved capable of upsetting more vaunted opponents this season, with Zenit St Petersburg and Tottenham among those to have been vanquished by Murat Yakin’s men.

“It will be one more difficult game for us,” added Luiz, whose teammate Ashley Cole is suspended for the return following his yellow card.

“Basel showed that against different teams and score away always.

“You need to keep strong in your mind, you need to keep focused because you need to win the second leg to be in the final.”

Chelsea have never lost a European semi-final at home and Basel have not won in England in nine attempts.