Everton reinforce their European credentials with a hard-earned win away to Champions League hopefuls West Ham.
After being fourth in the Premier League at the turn of the year, a run of six wins from 18 saw the Toffees slip to eighth.
But Ben Godfrey’s slide-rule pass allowed Calvert-Lewin to score his 16th league goal of the season in the first half at London Stadium.
And manager Carlo Ancelotti’s decision to play with three centre-backs was justified as his side defended resolutely to secure a second straight away win having also won 1-0 at Arsenal last month.
Everton remain eighth but are now one point behind seventh-placed Tottenham and three behind fifth-placed West Ham – with a game in hand on both.
The striker said: “I think every game is getting more important from now until the end of the season, so we simply have to keep believing and go into every game trying to win.”
Toffees boss Carlo Ancelotti added: “It was a vital victory, if we don’t win here we are out of the fight for Europe.
“There was pressure on the game but we managed the game well. We played defensively at the top, really good, and were really dangerous on the counter-attack.”
For the Hammers, this is a big blow to manager David Moyes’ hopes of again leading an unfancied team into the Champions League having done so as Everton boss in 2005.
Newcastle won at fourth-placed Leicester on Friday but this defeat keeps West Ham five points off the top four with just three games left.
A Europa League spot would be some consolation for Moyes and his former club aim to join West Ham after claiming their 11th away win in the league this season – and their fifth in London.
Frustrated Hammers fail to get a shot on target
After 34 games last season, West Ham were fifth from the bottom, three points above the relegation zone. At the same stage this term, they were five points off the top four.
Such has been the turnaround in Moyes’ first full season in charge, with victory at Everton on New Year’s Day sparking a run of 11 wins from 18 league games coming into this game.
That run was buoyed by the arrival of Jesse Lingard on loan, but despite dominating possession, Lingard and his team-mates struggled to play through Everton’s organised defence.
Their best chance of the first half saw Said Benrahma’s wait for his first Premier League goal continue as he headed over from a Pablo Fornals cross.
The Algeria winger has now had 32 attempts without scoring in the Premier League – more than any other player.
After the interval, Fornals had a shot blocked before spreading the play to Vladimir Coufal, whose low shot came back off the inside of the far post and substitute Jarrod Bowen was unable to steer the rebound goalwards.
Lingard was then booked for dissent as the visitors continued to frustrate the Hammers, who failed to register a shot on target.
Calvert-Lewin could have a big part to play at Euros
Ancelotti made three changes to the side beaten at home by Aston Villa last Saturday, bringing Michael Keane and Yerry Mina back into defence.
But Godfrey kept his place, as one of three centre-backs, in a system which allows defenders to step out of the backline when in possession and play the kind of ball that created Everton’s opener.
With West Ham’s defence seemingly set, Godfrey advanced into a pocket of space from halfway before spotting Calvert-Lewin’s run off Craig Dawson and the ex-Norwich defender slid a ball into the right channel for the England striker to latch on to and slot inside the far post.
While the Toffees remained dogged in defence, Calvert-Lewin showed why he is much more than just a goal threat and why he could be so valuable to England manager Gareth Southgate at the Euros.
Calvert-Lewin’s flick allowed Richarlison to test home goalkeeper Lukasz Fabianski with a close-range effort in the first half, and he showed great hold-up play before picking out Seamus Coleman’s run into the box late on, but the Everton captain’s shot was blocked.
The 24-year-old created another chance to seal victory as he rounded Fabianski before standing up a cross for substitute Joshua King, whose header came back off the post.
With Romelu Lukaku now the only Everton player to have scored more goals in a Premier League campaign, Calvert-Lewin could be a key man for England this summer.