Olivier Giroud's majestic injury-time header booked Chelsea's place in the knockout stages of the Champions League as they beat Rennes 2-1.

Callum Hudson-Odoi gave Chelsea a first-half lead (21) but it looked like Frank Lampard's side would rue some wayward finishing when Serhou Guirassy headed home unmarked from a corner (85).

Both teams looked happy with a draw but Giroud - who has aired concerns over a lack of game-time at the club - came off the bench to bravely head home (90) after Timo Werner was denied.

The result, helped by Sevilla's win in Krasnodar, means the Blues and the Spanish side are guaranteed to finish in the top two of Group E.

Ahead of Sunday's monster clash with Tottenham, live on Sky Sports, Lampard's side are now unbeaten in 13 games in all competitions (W6 D5) and have won their last six matches.

Player ratings

Rennes: Gomis (7), Traore (6), Da Silva (6), Nyamsi (6), Truffert (6), Bourigeaud (7), Nzonzi (6), Camavinga (6), Doku (6), Guirassy (7), Lea-Siliki (6)

Subs: Grenier (6), Niang (6), Gboho (6)

Chelsea: Mendy (8), Azpilicueta (7), Thiago Silva (8), Zouma (7), Chilwell (7), Kovacic (7), Jorginho (7), Mount (8), Werner (7), Abraham (7), Hudson-Odoi (8)

Subs: Kante (7), Giroud (8), Ziyech (7), Havertz (6), James (6)

Man of the match: Callum Hudson-Odoi

How Giroud sprung to save Chelsea…

After dispatching Rennes 3-0 in the corresponding fixture at Stamford Bridge, Chelsea looked in confident mood following their recent run of results.

Hudson-Odoi broke free on the right after just five minutes and put one on a plate for Werner from six yards out. However, the German somehow managed to sky the effort over the crossbar to leave his team-mates opened mouth in shock.

Ben Chilwell was causing problems for Rennes with his aggressive runs from full-back and Mount really should have doubled the lead after a Chilwell pull-back but was denied by a superb reflex stop from Gomis.

After being second best, that stop kicked Rennes into gear with Guirassy having more of an impact through the middle. James Lea Siliki had the chance to test his former team-mate Edouard Mendy when a fantastic chance dropped to him 15 yards out but his panicked effort blazed over the crossbar.

Werner had the ball in the net almost instantly after the restart but his header was rightly chalked off as he strayed half a yard offside.

Chelsea took their foot off the gas as the second half wore on with the French side growing in confidence and giving Mendy more to think about. The goalkeeper looked set to collect his eighth clean sheet in 10 Chelsea appearances when blocking a Gerzino Nyamsi header from a right-wing corner with 10 minutes to play.

However, Chelsea's inability to mark their men consistently from set-pieces was punished when Guirassy powered home a thumping header after Thiago Silva was caught under the ball.

With Krasnodar failing to pick up maximum points, Chelsea didn't need to find a winner to assure qualification but winning has become a habit for Lampard's side and Giroud popped up with a last-gasp moment of brilliance.

Werner raced through on goal but couldn't find a finish past Gomis - the chance looked lost but out of nowhere Giroud rose elegantly and powerfully above his marker to bullet a difficult header into the net.

Man of the match: Callum Hudson-Odoi

A classic example of how strength in depth within a squad can add extra motivation for players like Hudson-Odoi, who has been criticised for his inconsistency in the past.

Of course, it's easy to forget he's only just turned 20-years-old but when playing for a club like Chelsea, you have to learn quickly in terms of performing to a high-level on a weekly basis. Hudson-Odoi has given Lampard a selection headache after this performance where he took his goal with great class and skill and was unlucky not to grab a fantastic assist when Werner blazed over early on.

Hudson-Odoi certainly has a knack for the European occasion. Since his first European appearance for Chelsea in October 2018, he has netted six goals in European competition, a haul bettered only by Giroud for the Blues in that time (12).

Opta stats

Chelsea have made the knockout stages in 16 of their 17 Champions League seasons (only failing in 2012/13).

Chelsea have won three consecutive UEFA Champions League matches for the first time since December 2015.

Since the start of last season, Mount has registered eight assists for Chelsea in all competition, a joint-high among players still with the club (also 8 for Azpilicueta and Abraham).

What's next?

Lampard meets his former boss Jose Mourinho on Super Sunday when Spurs visit Stamford Bridge in what could be a huge game in the Premier League title race even at this early stage of the season.