Mark Noble struck twice from the penalty spot as West Ham beat Watford 3-1 at Upton Park to keep alive their faint hopes of a top-four place.
Andy Carroll gave the hosts the lead after 11 minutes on Wednesday night, and Noble added West Ham's second with the first of three penalties - two for West Ham - after Cheikhou Kouyate was fouled by Jose Holebas.
Almen Abdi's shirt-pull on Michail Antonio gave Noble another chance eight minutes after the break, and the Hammers midfielder coolly slotted home from 12 yards.
Watford were handed a lifeline when Sebastian Prodl slammed in a half-volley after 64 minutes, but substitute Troy Deeney saw his late penalty saved by Adrian before Nordin Amrabat was sent off for his second yellow card in the dying seconds.
Manchester United's 2-0 win over Crystal Palace means West Ham remain sixth, three points off fifth and a further point behind fourth-placed Arsenal, who face West Brom live on Sky Sports on Thursday.
Watford, with an FA Cup semi-final on Sunday, made seven changes but it was Carroll, one of three West Ham alterations from their 2-2 draw at Leicester, who opened the scoring.
The Hammers striker guided home Dimitri Payet's cross for his sixth goal in as many games.
Falling behind brought Watford to life, but with Odion Ighalo left out of the squad and Deeney on the bench, they lacked a focal point, and West Ham made them pay just before half-time.
Holebas was the villain for the visitors, climbing over the back of Kouyate, and referee Mike Dean had no hesitation in pointing to the spot.
Noble still had plenty to do against Heurelho Gomes, who saved two Saido Berahino penalties on Saturday, but the midfielder sent the goalkeeper the wrong way.
It could have been even better for the home side in first-half stoppage time, but Manuel Lanzini miscued wide when it looked easier to score.
Abdi spared his blushes shortly after the restart, turning Jose Manuel Jurado's cross over the bar and leaving manager Flores with his head in his hands on the sideline.
The Hornets midfielder capped a nightmare few minutes when he then conceded the second penalty of the evening for a pull on Antonio, duly dispatched by a grateful Noble.
But 11 minutes later Watford threatened to make a game of it as Prodl expertly fired home Steven Berghuis' free-kick.
The goal prompted Flores to introduce Ikechi Anya and Deeney, and the pair made a difference as Anya twice stretched the West Ham defence.
The hosts had chances to wrap up the points too, as Victor Moses and Lanzini both squandered clear-cut opportunities, but an Angelo Ogbonna shirt-pull on Prodl gave Deeney the perfect chance from the spot to set up a frantic finish.
The Hornets striker could not take it, though, as his poorly-struck spot-kick was kept out by Adrian.
Things got worse for the visitors in the closing stages when Amrabat, booked for a late challenge on Kouyate midway through the second half, saw red for a similarly mistimed lunge on Winston Reid deep into stoppage time.
Player ratings
West Ham: Adrian (7), Antonio (7), Reid (6), Ogbonna (6), Cresswell (6), Noble (8), Kouyate (7), Lanzini (7), Payet (7), Sakho (6), Carroll (7)
Subs used: Moses (6), Emenike (6), Collins (6)
Watford: Gomes (6), Paredes (6), Prodl (7), Cathcart (4), Holebas (3), Suarez (5), Behrami (5), Guedioura (6), Jurado (6), Abdi (6), Amrabat (6)
Sub used: Anya (6), Berghuis (6), Deeney (6)
Man of the match: Mark Noble