Arsenal boosted their hopes of a top-four finish in the Premier League after a bizarre 10th-minute goal by striker Pierre-Emerick Aubameyang gave them a 1-0 win at 10-man Watford on Monday.
The result lifted the Gunners two places up to fourth on 66 points from 33 games, one behind third-placed Tottenham Hotspur. Arsenal are ahead of fifth-placed Chelsea, who have played a game more, on goal difference. Watford stayed 10th with 46 points.
Arsenal manager Unai Emery was pleased with his team's first away clean sheet of the season.
"A clean sheet is very important," he told the BBC.
"It is going to give us a lot of information, this match."
The fast-paced clash took a decisive turn in a frantic one-minute spell early on, as Aubameyang found the back of the net in unlikely fashion before Watford striker Troy Deeney was shown a straight red card for elbowing Lucas Torreira.
The home side's goalkeeper Ben Foster dwelled on Daryl Janmaat's back pass for too long, allowing Aubameyang to close him down and block his attempted goalmouth clearance as the ball ricocheted into the back of the net.
Foster made no excuses for his howler.
"I've said sorry to the lads," he said.
"I tried to drag it on to my left and pass it out but before I knew it Aubameyang was bloody on me. He is too quick. In hindsight you have to get rid (of the ball) as quick as you can, even if it goes into row Z."
Despite their numerical disadvantage, Watford kept pressing and missed a string of chances to draw level, having twice been denied by the woodwork as well as by some good saves from Arsenal keeper Bernd Leno.
The home side missed their best opportunity in the 80th minute when Arsenal substitute Ainsley Maitland-Niles slid in to block Andre Gray's goal-bound effort after the Watford forward rounded Leno.
Aubameyang, Alex Iwobi and Henrikh Mkhitaryan also came close at the other end but Arsenal were forced to hang on in the closing stages with Watford throwing men forward.
The home team's manager Javi Gracia praised his team for their fighting spirit in the face of adversity.
"We did a lot of things to try to win, a big effort," he said. "We didn't get any points but we played well. It was a difficult game with 10 men."
Madrid stumble again in disappointing draw at Leganes
Real Madrid stumbled to a 1-1 La Liga draw at Leganes on Monday, the latest disappointing result in a nightmare season for the European champions.
Zinedine Zidane's side, who are third in the table and 13 points behind leaders Barcelona, were uninspired against local rivals Leganes.
Madrid, who were also knocked out of the Champions League at the last-16 stage by Ajax Amsterdam, put in the kind of lethargic performance which has plagued their season, with Marco Asensio and Raphael Varane missing good first-half chances.
Jonathan Silva fired Leganes ahead in the 45th minute with their first chance of the game, driving home from the edge of the box.
Karim Benzema equalised at the start of the second half and Marcelo saw a shot tipped away as Madrid enjoyed a short period in ascendancy.
Leganes, 11th in the table, went close to winning the game but Youssef En-Nesyri had a goal correctly disallowed for offside.
Madrid, playing on Monday for the first time in three years, in a slot reserved for teams not involved in Europe, produced a suitably subdued performance.
"It's a really tricky season for everyone, it's hard to explain and we all feel sad, but the situation is complicated," said Madrid goalkeeper Keylor Navas.
"In this club there's always pressure and that cannot be an excuse. We have to be mentally prepared. We are proud of this shirt and we love it."
Atalanta drop two precious points in Champions League race
Atalanta managed 32 shots on goal but could not find a way past Empoli keeper Bartlomiej Dragowski as they were held 0-0 at home and dropped two precious points in the race for a Champions League place on Monday.
The Polish goalkeeper had an outstanding match as he kept the hosts at bay with at least half a dozen top-quality saves.
Hans Hateboer wasted Atalanta's best chance when he contrived to head over from point-blank range from Josip Ilicic's assist after nine minutes.
After that, Atalanta laid siege to the Empoli goal but a combination of poor finishing, free kicks into the wall, heroic defending by the visitors and Dragowski prevented them from scoring.
The draw left Atalanta sixth in Serie A with 53 points, two behind fourth-placed AC Milan and one behind Roma. The top four qualify for the Champions League next season.
Empoli, 18th in the 20-team table, stayed in the relegation zone but are only two points behind Bologna, the team immediately above them.