Jamie Vardy is on the spot as Leicester prove too strong for West Brom

The last time Leicester won their opening match of the season, they went on to win the title. Only a crank would proclaim them future champions on the basis of this performance but it is fair to say this victory should do them good after their sorry end to last season. As for West Bromwich Albion, it would be nice to say things can only get better for them. But that is not true.

This was a chastening return to the top flight for West Brom after a two‑year exile. They started well but their lack of cutting edge was obvious, a failing they hope to address before the closure of the transfer window. Brendan Rodgers also hopes to recruit reinforcements and his case was helped by the fact that the breakthrough at the Hawthorns was made by Leicester’s sole new signing so far. Timothy Castagne, a defender bought for £21.5m from Atalanta, headed into the net in the 56th minute before Jamie Vardy secured three points by scoring two penalties. It was Leicester’s first away win in the league since 1 January.

Related: West Brom v Leicester: Premier League – live!

Slaven Bilic has promised West Brom will be bold as they fight for survival and the manager certainly succeeded in transmitting that attitude to his team, who cannot be accused of suffering from an inferiority complex. They pushed the visitors on to the back foot from the start but lacked potency when it came to the punch.

Leicester looked groggy in the early stages, partly because of the continuing absence of key players, although James Maddison was fit enough to appear off the bench in the second half.

Rodgers was forced to field an improvised defence, with Castagne slotting in at right-back while Wilfred Ndidi took up an unfamiliar role at centre-back. Bilic began with a new look out of choice, opting for a back three in a bid to nullify Vardy and release his team’s menace. The ploy worked well for a while and in attack Matheus Pereira, Grady Diangana and Callum Robinson made Leicester look lubberly with their bright skill and movement.

When Robinson flashed the ball across the face of goal in the ninth minute after nifty work by Diangana, no one could finish. With Leicester lethargic, West Brom worked their way into another threatening position in the 16th minute, goalkeeper Sam Johnstone dropping a long pass into the path of Darnell Furlong, who was chopped down at the edge of the area by James Justin. The left-back was booked but Diangana could not inflict further punishment from the free-kick.

It took Leicester half an hour to get up to speed. Once they did, West Brom looked doomed. Harvey Barnes had a fine game but frittered away a great chance to open the scoring, dabbing a volley at Johnstone from 10 yards. He made the keeper work harder two minutes later after cute interplay between Youri Tielemans and Justin but, after Johnstone saved, Barnes shanked the rebound wide with his right foot.

Leicester finally took the lead in the 11 minutes after half-time. Dennis Praet instigated the attack by conniving with Justin before clipping a delicate cross from the byline towards the back post, where Castagne arrived to beat two defenders and nod into the net.

As the confidence swelled, Leicester’s passing and running gained pep. They began to pull West Brom asunder. The hosts hung on until the 74th minute, when Kyle Bartley pulled back Vardy in the box an attempt to stop him collecting a pass from Barnes. There was no doubt what would happen next: Vardy, who had scored on every previous appearance at the Hawthorns, fired into the net. He did the same again when Dara O’Shea tripped Justin in the 84th minute.

“This is massive for us,” Vardy said. “Especially after our end to last season.”