There are a number of crucial clashes in the Premiership this weekend as the chasing pack continues to pursue Harlequins and Saracens who have opened up a healthy lead at the top of the standings.

Frontrunners Harlequins will be in action on Friday night when they travel to Franklin's Gardens to take on a third-placed Northampton Saints outfit that will be determined to continue their climb up the table with a strong performance.

The Leicester Tigers are another team that will be keen to continue their recent revival when they take on London Wasps at Welford Road, but they will face a fierce test from a Wasps side that have had their pride stung by a poor run of form recently.

On Sunday, second-placed Saracens entertain Bath who will also be keen to register a good result at Vicarage Road to lift themselves above their current ninth place on the standings.

Defending champions Saracens will be determined to keep Harlequins in their sights by securing another win in front of their home crowd.

We look at all of the Round 13 matches

Friday, January 6

Northampton Saints v Harlequins
(Franklin's Gardens, 19.45)

Northampton Saints have won their last three games in all competitions, and have lost just once at Franklin's Gardens in the Premiership this season: 13-14 to London Irish on 17 September.

Harlequins continue to top the Premiership table, seven points clear of chasing Saracens, following their 11-9 victory at Exeter on New Year's Eve. Quins have won their last eleven away encounters in all competitions since Bath beat them at The Rec on 16 April.

Harlequins won 26-13 when the two sides met earlier in the season, but have not achieved a season's double over the Saints since 2006/07. Quins have won on two of their last four visits to Franklin's Gardens.

The teams:

Northampton Saints: 15 Ben Foden, 14 Chris Ashton, 13 George Pisi, 12 James Downey, 11 Noah Cato, 10 Ryan Lamb, 9 Lee Dickson, 8 Roger Wilson, 7 Tom Wood, 6 Phil Dowson, 5 Mark Sorenson, 4 Samu Manoa, 3 Paul Doran Jones, 2 Dylan Hartley (captain), 1 Soane Tonga'Uiha.
Replacements: 16 Mike Haywood: 17 Alex Waller, 18 Brian Mujati, 19 Christian Day, 20 Ben Nutley, 21 Martin Roberts, 22 Stephen Myler, 23 Tom May.

Harlequins: 15 Mike Brown, 14 Tom Williams, 13 Matt Hopper, 12 Jordan Turner-Hall, 11 Ugo Monye, 10 Rory Clegg, 9 Danny Care, 8 Nick Easter, 7 Luke Wallace, 6 Chris Robshaw (captain), 5 George Robson, 4 Olly Kohn, 3 James Johnston, 2 Chris Brooker, 1 Joe Marler.
Replacements: 16 Joe Gray, 17 Mark Lambert, 18 Tim Fairbrother, 19 Tomas Vallejos, 20 Tom Guest, 21 Richard Bolt, 22 Benjamin Urdapilleta, 23 Sam Smith.

Referee: Dave Pearson

Saturday, January 7

Worcestor Warriors v Gloucester
(Sixways, 14.45)

Worcester Warriors have won three of their last four games in all competitions, the defeat being at home to in-form Leicester on 27 December. The Warriors have scored just nine tries in their 12 matches so far.

Gloucester are undefeated in their last four encounters, but their only away win since last February in the Premiership was 24-19 at Exeter Chiefs on November 5.

The Warriors have not beaten Gloucester since April 2009 at Kingsholm, whilst Gloucester have gained three wins and three losses on previous visits to Sixways in the Premiership.

The teams:

Worcestor Warriors: TBC

Gloucester: TBC

Referee: Martin Fox

Newcastle Falcons v Exeter Chiefs
(Kingston Park, 15.00)

Newcastle Falcons have slipped to three straight defeats in all competitions, whilst at Kingston Park their six game unbeaten run ended at the hands of Northampton Saints on New Year's Eve.

Exeter Chiefs lost both of their Premiership holiday fixtures, to London Irish and Harlequins. The Chiefs have won two of their last three away encounters.

Exeter won 32-15 when the two sides met at Sandy Park in September, and also won 23-13 on their most recent visit to Kingston Park, on February 18.

The teams:

Newcastle Falcons: TBC

Exeter Chiefs: TBC

Referee: Andrew Small

Leicester Tigers v London Wasps
(Welford Road, 17.00)

Leicester Tigers are the best team in the Premiership on current form, having attained 25 of a possible 30 points in their last six matches. Tigers have not been beaten in the Premiership since Harlequins visited Welford Road on 8 October.

London Wasps find themselves in 11th spot in the Premiership table – their lowest position this late in the season since 2001/02. Wasps were defeated 0-6 by Worcester at Adams Park on New Year’s Day – the first time they have ever been 'nilled' at home in a competitive match.

The last five encounters between the two clubs have all been won by the home side on the day. Wasps won 35-29 when they clashed at Adams Park in round two, whilst Wasps have not won at Welford Road since September 2008.

The teams:

Leicester Tigers: TBC

London Wasps: TBC

Referee: Tim Wigglesworth

Sunday, January 8

London Irish v Sale Sharks
(Madejski Stadium, 15.00)

London Irish’s last four games in the Premiership have all been won by the home side on the day, however the Exiles have won just two of their last five matches at Madejski Stadium in all competitions.

Sale Sharks' four game winning run ended at Leicester on New Year's Day. The Sharks’ only away win in the Premiership since round three was 16-13 at Bath on December 3.

Sale won 30-29 at Edgeley Park when the two sides met in round two, and are going for a first season's double over the Exiles since 2005/06.

The teams:

London Irish: TBC

Sale Sharks: TBC

Referee: Wayne Barnes

Saracens v Bath
(Vicarage Road, 15.00)

Saracens are unbeaten in their last five matches in all competitions, whilst they have been defeated just once at Vicarage Road in the Premiership since February 2010 when Bath were the visitors.

Bath's unwanted five game losing streak ended with their 30-3 victory at home to London Irish on New Year's Day. Bath have lost four in a row on the road since their 13-12 win against the Exiles at Madejski Stadium in the Premiership on October 29.

Saracens have won their last three encounters with Bath, whilst Bath's solitary Premiership victory at Vicarage Road since 2003 was 16-14 on 28February 2010.

The teams:

Saracens: TBC

Bath: TBC

Referee: Pascal Gauzere (France)