Pierre-Emerick Aubameyang struck twice as Arsenal climbed back into contention to qualify for Europe next season with a 4-0 thrashing of Norwich, while Leicester's slide continued in a 2-1 defeat at Everton.
Aubameyang moved alongside Jamie Vardy as the Premier League's top scorer on 19 goals on a night of contrasting fortunes for the Golden Boot contenders.
Arsenal registered a third straight win to move up to seventh against a Norwich side ever more resigned to relegation.
Canaries captain Tim Krul did his side no favours by gifting the opener to Aubameyang when he was caught trying to dribble past the Gabon international.
Aubameyang's first saw him reach 50 Premier League goals in 79 appearances - making him the fastest Arsenal player to reach that landmark.
"A player that is able to score as many goals as he has done in that short space of time tells you everything about the importance that he has for us," said Arsenal boss Mikel Arteta.
Aubameyang turned provider for Granit Xhaka to make it 2-0 before half-time and was then handed another gift when Norwich striker Josip Drmic teed him up to make it 3-0.
Cedric Soares signed a four-year deal at the Emirates last week without having played a minute for the Gunners since joining on loan from Southampton in January.
But the Portuguese right-back made his debut one to remember with a long-range strike nine minutes from time to round off the scoring.
Leicester are headed in the opposite direction as their winless run since English football's restart from the coronavirus pandemic stretched to four games.
Richarlison and Gylfi Sigurdsson's penalty gave Everton the perfect start at Goodison Park.
The Toffees are yet to lose at home under Carlo Ancelotti and they held on in the second half for a vital three points for their own ambitions of European football next season.
Kelechi Iheanacho's fortunate goal as the ball ricocheted in off his face reduced Leicester's arrears and they pressed hard for an equaliser in the closing stages.
Michael Keane's clearance off the line spared Jordan Pickford's blushes after another huge error from the England number one.
However, defeat means Leicester could drop to fourth should Chelsea win at West Ham later on Wednesday and the Foxes are now just three points clear of Manchester United and Wolves in the battle for a place in the Champions League next season.
"Our form hasn't been the best for a period now but we still have it in our hands to achieve what would be a dream for us, getting into the top four, said Leicester boss Brendan Rodgers. "But we can only get that if the performance is right."
At the bottom of the table, Bournemouth also suffered a huge blow in their battle to beat the drop with a humiliating 4-1 home defeat by Newcastle.
Dwight Gayle, Sean Longstaff, Miguel Almiron and Valentino Lozaro were on target for the Magpies, who were not distracted by the ongoing uncertainty around the club over a proposed Saudi takeover.
Bournemouth remain in the bottom three and the margin of defeat could also prove costly as they drop below Aston Villa on goal difference into 19th.
"The players are playing slightly tense, you could say understandably with the position they are in," said Bournemouth boss Eddie Howe. "I urge them to play the game and not the situation but they are struggling a bit under the weight of that."