Chelsea topped the Premier League with a hard 2-1 win at Vicarage Road but were taken all the way by a stubborn Watford side on a challenging night for Thomas Tuchel's side.
The much changed Blues looked disgruntled in the opening exchanges, with medical staff members from both teams assisting paramedics in the stands, before play was temporarily suspended due to a medical emergency after a supporter fell ill. This gave Tuchel a chance to drill some urgency into his players, and Mason Mount took the lead from close after hitting a few minutes before the woodwork.
The hosts bounced back through Emmanuel Dennis, who found the corner to make it 1-1, but the champions find a way to win when they are up against it, and that's exactly what Chelsea did. Mount was involved again, this time teasing Hakim Ziyech, who had a clinical sophistication to break Watford's hearts.
Manager rating
Thomas Tuchel, 6 - Six variations, and it showed. Even the best teams need to know when not to play from behind, but their team fails to recognize it. Managers are judged on results though, and Chelsea were eventually helped out by some smart replacements.
Negatives
Chelsea had no answer to their unreliable hosts, who got their opponents themselves into all kinds of trouble. The Blues were second in the entire park for big spells, and they can't afford several nights like this to raise silverware in May.
Positives
The biggest positive of the night is the immediate response of the medical teams, who swiftly attended to emergencies in the stands.
Player ratings
GK Edouard Mendy, 7 - Chelsea's goalkeeper might not have expected a touch inside the first minute, but he was his side's busiest player from off and flying to keep the Blues level before denying Danny Rose was forced to save. close range.
DF Trevoh Chaloba, 7 - The 22-year-old provided some significant restraint in tough conditions and was set to score a dangerous sweep attempt in the right place at the right time, with Vicarage Road ready to burst. A good show before he left.
DF Andreas Christensen, 5 -- Needed early treatment after a painful clash with Joshua King as Chelsea struggle to survive their half. Crucially on hand to smash the ball to safety after Rose was denied by Mendy, but he always looked weak.
DF Antonio Rudiger, 5 - Wrongly cleared across the park. He was too easily beaten by Dennis, who shot to his feet and into the corner, but opened the attack that made it 2-1 to the left with a smart, scooped pass out.
MF Cesar Azpilicueta, 5 -- Joo Pedro's pressure survived a heartbreaking moment when a whipped cross from Kiko Femania hit a knee cannon and was beaten by Mendy. Struggled against a Watford attack that was full of momentum.
MF Ruben Loftus-Cheek, 6 -- The athletic midfielder made little impact in the first half, where apart from on target, Chelsea struggled to put together good runs. Much better after the break, and he cleverly removed Christian Pulisic after a powerful explosion.
MF Saul Nigge, 4 - He was practically invisible in the middle and his only contribution of note was when he was spotted in yellow for a bridge over Dennis.
MF Marcos Alonso, 8 -- A tough night defensively, but he was the architect of the opening goal when he slotted in Kai Havertz, who scored 1-0. More importantly, he helped alert the medical staff to the fan in need of immediate attention, and the rest turned out to be insignificant.
FW Mason Mount, 9 -- The game came within inches of the scoring opening against the race when his sweet-tempered effort from a narrow angle shattered the left post. It was before he took Chelsea out past close range, and it crossed for Ziyech to snatch all three points.
FW Christian Pulisic, 6 - He tried his best to provide an outlet, but had little success in the opening 45 minutes. Overjoyed after the break but lost his leg at the crucial moment when he looked destined to score. Ended the night on the right wing back.
FW Kai Havertz, 7 - Totally isolated for about half an hour, but when he selflessly put the ball on a plate to drill home to mount, he caught himself to an assist took. When he moved his marker he scrambled the hosts after the break, but his teasing low pass was defended.
Substitutes
DF Thiago Silva, 6 -- On the break with Chaloba pushed Niguez into midfield, but he didn't really do much until the final moments, when he helped his side survive a wave of late pressure.
MF Hakim Ziyech, 7 -- Injured Chaloba was replaced at the hour mark and Tuchel was forced to reshuffle the pack again. He picked up a yellow card in less than five minutes and his demise was nothing short of impressive, but he grabbed the headlines when he crashed home with a force majeure.
FW Romelu Lukaku, 6 -- He worked with a formidable defense when he replaced Azpilicueta as Tuchel went all in but it was in his own box where he made his biggest contribution, with a huge header. relieved the pressure.