Ole Gunnar Solskjaer urged his Manchester United stars to seize a "fantastic opportunity" to qualify for the Champions League after Mason Greenwood rescued a 1-1 draw against West Ham on Wednesday.
Solskjaer's side fell behind to Michail Antonio's penalty in the first half at Old Trafford.
But teenage forward Greenwood struck after the interval to lift United into third place in the Premier League.
They are ahead of fourth-placed Chelsea on goal difference after the Blues lost 5-3 at champions Liverpool.
United will finish in the top four if they draw or win in their decisive showdown with fifth-placed Leicester on Sunday.
United are one point ahead of Leicester going into their last game of the season at the King Power Stadium.
"When we started after the lockdown, we had to go for it. We had to go for goal difference, we had to go for points," Solskjaer said.
"The effort has been fantastic and the results have been fantastic.
"Going into half-time we knew that wasn't the result we wanted. But you can't expect to turn teams over like we needed to have a different scenario for Sunday.
"We've given ourselves a fantastic opportunity and a great starting point for Sunday."
Solskjaer's team were well below their best against West Ham, but they are now unbeaten in 13 league matches and will complete an impressive surge into the Champions League if they emerge unscathed at Leicester.
They can also qualify for Europe's elite club competition if they win the Europa League in August.
Solskjaer will have been relieved there were no costly mistakes from David De Gea after the United keeper retained his place.
The Spaniard made two embarrassing errors that led to goals in United's 3-1 FA Cup semi-final defeat against Chelsea on Sunday.
West Ham's point ensured they are mathematically certain to avoid relegation.
After their sluggish loss at Wembley ended a 19-match unbeaten run in all competitions, Solskjaer's men made a more enterprising start this time and West Ham keeper Lukasz Fabianski was tested twice inside the first four minutes.
Anthony Martial's stinging strike from just inside the penalty area forced an excellent save from Fabianski, who then plunged to his right to keep out Greenwood's effort.
Rashford tried his luck from 30 yards, but the forward's powerful drive was too close to Fabianski, while Greenwood's close-range shot was blocked by Ogbonna.
De Gea had been a spectator for the first 40 minutes and when he was finally called into action, Antonio's header lacked the power to trouble him.
But De Gea still had to pick the ball out of the net moments before half-time after Paul Pogba handed West Ham a penalty.
Declan Rice's free-kick was smashed straight at Pogba, who instinctively stuck up his arms to protect his face.
Despite Pogba dropping to the turf as though he had been hit in the head, VAR confirmed the France midfielder's handball.
Antonio took the spot-kick, sending De Gea the wrong way for his sixth goal in his last three games.
United had let the first half drift out of their control, but Greenwood dragged them level with another demonstration of his remarkable maturity in the 51st minute.
Dropping deep to exchange passes with Martial, the 18-year-old kept his composure to drill a clinical finish past Fabianski from 12 yards.
Feature image courtesy: AFP / Catherine Ivill