The returning Diego Costa played a key role

The returning Diego Costa played a key role as Chelsea earned a much-needed win over struggling Aston Villa.

The striker tapped in Willian's pass midway through the first half after defender Joleon Lescott's mis-control gifted the ball to the home side.
It was a welcome break for the Blues, who doubled their lead when Villa's Alan Hutton deflected in Costa's shot.
Chelsea, 16th in the table at the start of the day, were not at their best - but Villa offered little.
What contributions Tim Sherwood's side did make to the game were all in Chelsea's favour as they repeatedly gave the ball away and were punished accordingly.
They remain in 18th place and without a win in their past eight matches.
Chelsea's second home win of the season moves them up to 11th in the table, five points behind fourth place.

Five keys to success

Diego Costa provided much more of a threat in attack than Radamel Falcao had during the Spaniard's absence

In May, BBC Sport suggested five areas key to Chelsea's title win last season: Costa's goals, the creativity of their midfield, their defensive steel, winning mentality and the influence of manager Jose Mourinho.
The Blues' poor start to this season - which prior to this match was their worst since 1978 - is as much down to a failure of this crucial quintet.
Costa had not scored enough, Cesc Fabregas and Eden Hazard created little and they had conceded two or more goals in seven of their eight games.
Their edge was gone and, from the outside at least, their boss seemed more focused on criticising his recent Football Association fine than defending the title.
While Saturday was far from a return to the ruthless form of last season, it did showcase a notable improvement on previous home games.
Costa scored on his return from a three-match ban for violent conduct, the midfield - which included 19-year-old Ruben Loftus-Cheek until his removal at the break - offered more, they kept their first clean sheet in five games and saw the game out professionally.
Chelsea's desire was epitomised in one incident, 20 minutes from time when a group of Blues defenders flung themselves at the feet of Lescott to prevent him poking the ball in from close range to give Villa a foothold back in the game.

Villans in need of some heroes

Sherwood only took over at Villa in February, after which he saved them from relegation and led them to the FA Cup final - achievements that should earn him time in his job.
They started reasonably well at Stamford Bridge, keeping Chelsea at bay with a packed midfield and occasionally breaking with purpose, albeit with no end product.
Jack Grealish was lively for 20 minutes on his return to the side and Rudy Gestede proved a physical challenge for Blues captain John Terry on the few occasions the ball came near him.
But Sherwood - and his bosses - should be concerned by the mistakes that regularly gifted Chelsea possession and ultimately the win, as well as the way the players meekly accepted a fifth straight defeat once Costa's low shot had found the net off Hutton's boot.
More to follow.

Lineup, Bookings (4) & Substitutions (5)

Chelsea

• 01 Begovic
• 28 Azpilicueta
• 05 Zouma
• 26 Terry
• 06 Baba
• 07 Ramires
• 04 Fàbregas
• 22 Willian Booked (Remy - 92' )
• 36 Loftus-Cheek (Matic - 45' )
• 17 Pedro (Hazard - 83' )
• 19 Diego Costa

Substitutes

• 08 Oscar
• 10 Hazard
• 12 Mikel
• 18 Remy
• 21 Matic
• 24 Cahill
• 27 Blackman

Aston Villa

• 01 Guzan
• 21 Hutton
• 04 Richards
• 16 Lescott
• 18 Richardson Booked (Amavi - 64' )
• 15 Westwood
• 08 Gueye
• 25 Gil
• 40 Grealish Booked
• 19 J Ayew Booked (Traoré - 68' )
• 39 Gestede

Substitutes

• 07 Bacuna
• 09 Sinclair
• 20 Traoré
• 23 Amavi
• 24 Sánchez
• 31 Bunn
• 33 Crespo

Ref: Roger East

Att: 41,596

Match Stats

Shots

9 8

On target

3 1

Corners

4 4

Fouls

22 17

Live Text Commentary

Full time

Full Time Match ends, Chelsea 2, Aston Villa 0.

90:00 +4:02 Full time

Full Time Second Half ends, Chelsea 2, Aston Villa 0.

90:00 +1:20 Substitution

Substitution Substitution, Chelsea. Loïc Remy replaces Willian.

88:34 Corner, Chelsea. Conceded by Ashley Westwood.
86:29 Foul by Idrissa Gueye (Aston Villa).
86:29 Willian (Chelsea) wins a free kick on the right wing.
84:57 Booking

Booking Jack Grealish (Aston Villa) is shown the yellow card for a bad foul.

84:52 Foul by Jack Grealish (Aston Villa).
84:52 César Azpilicueta (Chelsea) wins a free kick in the defensive half.
83:42 Corner, Aston Villa. Conceded by Nemanja Matic.
82:31 Substitution

Substitution Substitution, Chelsea. Eden Hazard replaces Pedro.

81:28 Foul by Micah Richards (Aston Villa).
81:28 Diego Costa (Chelsea) wins a free kick in the defensive half.
80:42 Adama Traoré (Aston Villa) wins a free kick in the defensive half.
80:42 Foul by Diego Costa (Chelsea).
79:55 Attempt missed. Cesc Fàbregas (Chelsea) right footed shot from a difficult angle on the right misses to the left. Assisted by Willian with a through ball.
79:05 Adama Traoré (Aston Villa) wins a free kick in the attacking half.
79:05 Foul by Baba Rahman (Chelsea).
77:29 Attempt blocked. Pedro (Chelsea) right footed shot from outside the box is blocked. Assisted by Cesc Fàbregas.
76:51 Corner, Aston Villa. Conceded by Baba Rahman.