Chelseas Diego Costa scored his 10th league goal of the season to earn a 1-0 win at Middlesbrough and put them top of the Premier League by a point
Goodness knows how high on the scale Antonio Contes blood pressure might have registered had he nipped out at half-time and visited the NHS health bus in Middlesbroughs carpark offering fans mini check-ups.
Watching the Italians technical-area histrionics it would have been easy to imagine his side were locked in a desperate relegation struggle rather than en route to going top of the Premier League courtesy of a sixth successive win.
Considering Chelsea have failed to concede a single goal during that sequence Conte generally has cause for serenity but on this occasion at least, his extreme agitation was at least partially justified by an ultra-determined, sporadically dangerous Middlesbrough.
No matter that Diego Costas winning volley from a badly defended corner reignited Teessides relegation worries, Adama Traors pace and the midfield steel of Aitor Karankas two Adams, Clayton and Forshaw, left Chelsea looking slightly relieved to escape with all three points.
Karankas switch from his beloved, if sometimes rather rigid, 4231 formation to a much more flexible version of 433 helped a recent mini-renaissance featuring draws at Arsenal and Manchester City. It did not serve him too badly here either but Boros problem is that while they never look in danger of a thrashing they have won only twice all season and have a costly habit of making one unfortunate error per match.
The Teesside side started well with Gastn Ramrez troubling Victor Moses, the right wing-back in Contes transformative 3-4-3 system, and helping create an early chance which saw lvaro Negredo seeking his first goal since the seasons opening day slice over from six yards. Unfortunately it proved to be the cue for a disappointing, less than mobile afternoon for the Spanish centre-forward which must have made Jordan Rhodes, once again sidelined, wonder precisely what he has to do to get a game.
If only Negredo had shown some of Ramrezs ambition. Later, some woeful decision-making would let the Uruguayan down but, initially, he briefly looked capable of eclipsing even Eden Hazard although it hardly helped the latters cause that he appeared to be singled out for some rough stuff by Karankas midfield.
After seeing Hazard clattered by a trio of early challenges, Jon Moss, the referee, finally booked Clayton for a particularly ruthless late lunge at the Belgians ankle.
If Hazards targeting cannot have been a shock, Conte looked affronted by Boros surprisingly effective amalgam of caution and aggression. Superbly compact as Chelsea advanced, with Clayton and Forshaw intelligence personified, Karankas players were not frightened to counterattack, utilising Traors blistering, if ill-disciplined, pace to, at times, perturb the visiting back three.
It meant, until Costas goal, Victor Valds enjoyed a fairly peaceful first half. Admittedly the former Barcelona and Manchester United goalkeeper made one outstanding save when he diverted Pedros goalbound shot for a corner following exemplary approach work from Hazard and Moses, but he was largely well protected.
As half-time approached Costa had been largely anonymous, with Ben Gibson and Calum Chambers keeping him uncommonly quiet but then, in the 41st minute, a chance finally fell the centre-forwards way and, typically, he was in the right place at the right time to seize it.
Hazard sent a corner looping high into the raw November air and no Boro player reacted properly. Valds, who had just received lengthy treatment for an injury, should arguably have come for the ball as it looped up, while Gibson and Marten de Roon were among those who seemed to lose concentration. It left Costa free to meet a deflection, extend his left foot and volley his 10th goal of the season into the bottom corner from six yards.
As befits a world-class striker, he needed only a single opening to score but Costa had already caught the eye courtesy of some radically improved discipline. Hats off to Conte for eliminating the frequent am-dram theatrics which so annoyed opponents and officials when the striker served under Jos Mourinho.
With Chelsea galvanised, the second half began with Moses and Hazard creating an opening for Marcos Alonso guilty of an earlier bad miss repelled by Valds, with Chambers then doing well to block Pedros attempt to pounce on the rebound.
By now Moses was increasingly influential as he delighted in reminding everyone that Fbio da Silva was deputising for the injured George Friend at left-back and it was his first appearance of the season. Sensibly Karanka replaced DaSilva with Stewart Downing after an hour.
As icy rain poured down Clayton and DeRoon began reasserting themselves against NGolo Kant and co, and Ramrez shot over the bar.
Chelseas minds seemed to be suddenly wandering and it took some extreme touchline gyrations from Conte cutting an infinitely livelier, more agile figure than Negredo until they refocused and Pedros shot hit the bar following fine work from David Luiz and Costa.
Deep into the second half Thibaut Courtois had still to make a significant save but when the call to arms eventually came Chelseas goalkeeper proved equal to it, saving Negredos shot superbly after Traors pace caught his defence cold.
Middlesbrough are unlikely to be the last team similarly thwarted by Courtois, Costa and co.