Chelsea match winner Diego Costa playing a dangerous game
Watford 1-2 Chelsea
If Chelsea are to rely on Diego Costa for late winning goals this season, as has happened in both Premier League games so far, they will need to ensure that he is still on the pitch.
At Watford on Saturday, just as against West Ham in last Monday's success by the same score, he could easily have been dismissed by a stricter referee shortly before coming up with the decisive strike. Once more he had been shown a yellow card for dissent, in this case claiming to have been fouled before Watford broke away to take the lead with a fierce shot from Etienne Capoue.
A second card should probably have followed for a theatrical dive as Chelsea found some belated urgency, inspired by manager Antonio Conte's three substitutions.
Instead, the Spanish international was able to pounce onto a perfect through pass from one of the replacements, Cesc Fabregas, and beat Heurelho Gomes, who had earlier failed to hold Eden Hazard's low drive, allowing Michy Batshuayi, another substitute, to equalise.
Conte agreed that the first card was deserved but was not prepared to agree that a second should have been shown. A passionate man, he admires similar qualities in his main striker, but has already found it necessary to warn him about improving his disciplinary record.
"Diego must be focused on the game and not take notice of other players, or managers or the press," Conte said.
"It's important to pay attention during the game. He's an important player. He can score a lot of goals and I want him to put himself in the game and not think of other situations. I try to speak with all my players and with them individually too.
"But what I say to them I prefer to keep between me and them."
The message is hardly a secret.
One consolation is that if and when Costa suffers an almost inevitable ban - there were two prolonged ones last season - Chelsea have in Batshuayi a £33m striker who could prove worth something close to the "crazy" prices Conte has complained about.
Only once last season did Chelsea manage to win successive league games, a shocking record for defending champions.
"It was important in these two games to win because you can continue to work as confidence rises," Conte said. "So far I am happy."
So are the club's supporters, already won over by an emotional man whose touchline animation makes Jose Mourinho look a shrinking violet, yet still remains sufficiently composed to change the personnel and tactics to good effect.
"When my team plays, I play with them on the touchline," he explained.
"I try in every moment to suggest the right pass or the right position. It's important because sometimes when the play is open on one side it's important to shout. Then at the end of the game when you play with 4-2-4 to shout for them to stay very wide. I know sometimes they hear and sometimes they choose not to."
His compatriot Walter Mazzarri, almost restrained in comparison, saw promise in Watford's first 70 minutes.
They have quietly spent about £40m this summer, although an oddity on Saturday was that there were more new managers than players starting the game.
WATFORD: Gomes, Cathcart, Prodl, Britos, Amrabat, Behrami, Capoue (Doucoure, 84 mins), Guedioura (Vydra, 89 mins), Holebas (Zuniga, 90 mins), Deeney, Ighalo. Unused subs: Pantilimon, Nyom, Anya, Hoban.
CHELSEA: Courtois, Ivanovic, Cahill, Terry, Azpilicueta; Kante, Pedro (Moses, 71 mins), Oscar (Batshuayi, 73 mins), Matic (Fabregas, 78 mins), Hazard, Costa. Unused subs: Begovic, Aina, Loftus-Cheek, Chalobah.
Referee: Jon Moss (West Yorkshire)
Man of the match: Etienne Capoue
Match rating: 6/10