While some groups are beginning to take shape ahead of matchweek four in the Champions League, there is still plenty to play for as we enter a pivotal round of fixtures.

We preview the pick of the action as the knockout stages edge into view.

Chelsea to continue strong start?

Chelsea can continue their impressive start to the season by qualifying for the Champions League knockout stages with two games to spare if results go their way this week. The Blues are looking for their third successive win in the Champions League in Tuesday night’s early kick-off in Rennes, a feat they haven’t achieved since 2015.

Chelsea’s last game in this competition came against Julien Stéphan’s Rennes side, although he’ll be hoping they can provide more of a challenge than they did in their 3-0 defeat at Stamford Bridge. Rennes are winless in their first three games at Europe’s top table but host only their second home game of the group stage so far after drawing with Krasnodar in matchweek one.

Although Chelsea may have to fight with Sevilla for top spot in Group E, they have been dominant so far and are yet to concede a goal in the competition. Frank Lampard’s side are currently 1/2 to pick up another crucial win on Tuesday, while Rennes could give themselves some hope of reaching the knockout stages with a win at 11/2.

PSG and RB Leipzig meet again

Last year’s runners-up PSG face RB Leipzig for the third time in under 100 days on Tuesday, with both sides previously picking up victories against each other. Julian Nagelsmann’s Leipzig side clinched theirs when the sides met in matchweek two and can give themselves a great chance of reaching the second round for consecutive seasons, perhaps at the expense of the Parisians.

With two defeats on the board for PSG already, as well as a trip to Old Trafford to come, nobody will need reminding of the importance of this one more than Thomas Tuchel. Such games are the making or breaking of managers at the Parc des Princes, and Europa League qualification will likely do little to satisfy the crowds or owners at PSG should they fail to make the knockout stages in the Champions League.

A pivotal win for PSG on Tuesday is currently available at 13/20, with Leipzig 19/5 to ensure the Parisians’ lose consecutive home games in the Champions League for the first time.

Inter and Real in crunch clash

A crunch clash in Group B comes to a head at the San Siro on Wednesday night, as bottom-of-the-group Inter Milan look for a vital victory against Real Madrid, who have had their share of stumbles in the competition so far, sitting third. It won’t be simple for either to qualify, with all four teams in the group still in the conversation going into matchweek four.

With group rivals Borussia Monchengladbach hosting Shakhtar Donetsk in the other fixture, victory for either side will put them in pole position to qualify, likely at the expense of either Inter or Madrid. If there’s a result either way in that game, particularly if Monchengladbach prevail, it becomes increasingly inevitable that at least one of these European giants will be taking an early bath.

The omens look good for Inter, having never previously lost to the 13-time European champions at home in European competition. If they do fail to win, however, it will be the first time they have failed to win any of their first four Champions League games and leaves them in a bleak position with two to play.

Madrid, on the other hand, are level on points with second-placed Shakhtar and would land a significant blow in the fight for a top-two finish by winning in Milan. They’ve won seven of their previous eight European fixtures against Italian opposition under Zinedine Zidane, scoring more than once in each of those wins.

Inter are currently 11/10 to claim a crucial win, with Madrid 9/4 to come away with three points.

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