Bolton 0, Chelsea 1:  Chelsea won this game with a goal that Bolton will argue in sheer annoyance had come beyond the end of the stoppage- time indicated for the first half. The winners will prefer to regard that as truth of their ability to play hard for as long as possible. Only Michael Ballack's header in that incident separated the teams in the end.

This completed a very satisfactory pair of fixtures for Chelsea in the north-west of England. After the draw at Manchester United this success must deepen the belief that they will prove too consistent and competitive to be denied in the Premiership.

Bolton's manager Sam Allardyce had been contemptuous of Arsenal, who keep on losing to his team, as they did on Saturday. He returned to the topic in his programme notes, sneering that his opposite number Arsene Wenger will "always look for excuses".

Allardyce must have a very different opinion about last night's opponents. Chelsea have, in fact, been all to happy to deal with Bolton's style on this ground. Chelsea won the Premiership title here in 2005 and quickly retained it with another victory at the Reebok earlier this year.

The champions have the power to relish any kind of battle and, without the injured Joe Cole or Arjen Robben even on the bench, the physical toughness of Jose Mourinho's team was at its most accentuated.

They had slightly the better of the play before the interval. The force of the midfield was unmistakable, as it had been in the draw at Old Trafford on Sunday, but it did seem for a while that there was once more a failure for Andriy Shevchenko in the forward line. Many would have felt the Ukrainian was fortunate to be in the starting line-up at all.

That impression changed dramatically in the last few moments of the first half. The Ukrainian gathered on the left, turned inside and ran on to hit an excellent drive that Jussi Jaaskelainen did well to turn behind.

Bolton believed the half should have stopped then with two minutes of stoppage-time completed but the referee Steve Bennett allowed Frank Lampard to take the corner from the left. Ballack eluded Kevin Davies at the near post to head into the net.

Set-pieces had been a surprising weakness in Allardyce's team. They had been unpicked at an earlier corner as well. Lampard, after 21 minutes, had struck it deep for Ricardo Carvalho to head against the post.

The Portugal defender seemed to dive in a later incident and Ivan Campo was booked for shoving him in the aftermath.

Carvalho himself would eventually be cautioned for a foul on Davies, but this game did not seem to be at risk of lapsing into petty disputes, even if Nicolas Anelka twice went down under Chelsea challenges, protesting bitterly.

It was a well-contested fixture, with enough football to quell any accusation of too much emphasis on muscle. Early in the second half, a Frank Lampard free-kick had to be saved, and in the 53rd minute El Hadji Diouf's similar effort had to be dealt with by Carlo Cudicini.

Chelsea's superiority had depended, as it so often does, on the commanding character of the midfield. Few sides are equipped to equal it, but Bolton are not readily ground down.

A run across field by Nicky Hunt was met by Nicholas Anelka in the 56th minute. The Frenchman's head, luckily for the visitors, is nowhere near as effective as the feet that scored both goals against Arsenal, and he directed the ball across the face of goal.

The defenders were too well co-ordinated for goalmouth action to arrive constantly. When Geremi curled a good cross from the right after 66 minutes, an alert Jaaskelainen punched the ball away before Didier Drogba could connect.

It is fixtures of this nature that have been the foundation of Chelsea's consecutive triumphs in the Premiership.

The toughness normally proves decisive. Mourinho would like to suppose that a trend is emerging once again. It is a curious fact, though, that Chelsea's two Premiership defeats this season, at Middlesbrough and Tottenham, have come after they had taken the lead.

Bolton conducted themselves as if they believed vulnerability might still exist in Chelsea's ranks. With 11 minutes left, Cudicini had to dive to beat away an attempt on the turn from Diouf.

By then, Shevchenko had been removed, after failing to add to the contribution he had made before Chelsea's goal.

His place went to Salomon Kalou, a youngster. It was natural that Mourinho should look for a new supply of energy in a highly taxing fixture, and afterwards he described his players as "heroes" after withstanding constant in pressure in the second half.

He said: "In the first half we played amazingly well. I don't remember Bolton even touching our box and the goal in the last few seconds was more than justice.

"In the second half they put pressure on us and played very well and we defended very well. We had in every player a fighter because we had to fight for every ball. It is difficult to play against them."

BOLTON:Jaaskelainen, Hunt, Faye, Meite, Ben Haim, Nolan, Campo, Speed, Davies (Vaz Te 76), Anelka, Diouf. Subs Not Used: Al Habsi, Giannakopoulos, Pedersen, Tal. Booked: Campo, Faye, Nolan.

CHELSEA:Cudicini, Geremi, Carvalho, Terry, Ashley Cole, Essien, Makelele, Lampard, Ballack, Shevchenko (Kalou 77), Drogba (Mikel 90). Subs Not Used: Hilario, Boulahrouz, Wright-Phillips. Booked: Carvalho.

Referee:S Bennett (Kent).