London Irish maintained their 100% winning start to the Premiership Rugby Cup with a nervy win over Saracens.

A late penalty from Jamie Benson edged Harlequins to a thrilling rollercoaster 26-25 win over Northampton Saints.

And defending champions Sale finished strongly to seal a comeback victory over Newcastle Falcons.

London Irish’s match with Saracens was a meeting of the two winners from the first round in Pool Three.

And the Exiles, helped by a yellow card for a deliberate knock-on by Elliott Obatoyinbo, stormed into a 21-0 lead through scores from Ollie Hassell-Collins, Terrence Hepetema on his 50th appearance for the club and a Steve Mafi snipe from close range.

Sarries re-grouped at the break and finally got on the board when Rotimi Segun finished in the corner from Manu Vunipola’s arrowed kick.

But Cillian Redmond quickly rounded off a flowing team move to grab Irish’s bonus-point try and restore their 21-point lead.

Saracens again dug deep and two tries in three minutes from wing Ben Harris suddenly had the visitors within range. Vunipola then slotted a penalty to cut the gap to six entering the last 10 minutes.

Irish had a chance to settle their nerves when Jennings missed from the tee moments later but with the clock nearing the red zone, the fly-half did not waste a second chance, seeing his kick hit both posts before bouncing over for a 29-20 win.

Harlequins started brilliantly against Northampton, racing into a 14-0 lead after 10 minutes with Lennox Anyanwu powering over from a five-metre scrum and Scott Steele rounding off a fine break from Aaron Morris.

Saints then responded superbly themselves with George Hendy sent through by Scotland international Rory Hutchinson to score before Mikey Haywood scored his first try on his first start of the season after good work from a driving maul.

Josh Gillespie’s predatory finish from a Saints scrum 10 metres out edged them in front by the break with 10 unanswered points.

Hooker Jack Musk dropped the ball with the line at his mercy as Quins wasted the chance to level before James Grayson’s penalty put Saints eight points in front.

But yellow cards to JJ Tonks and Tom Collins had Saints down to 13 players and Quins took full advantage as Anyanwu’s second try and Luke Wallace’s lunge over the line, after Huw Jones had been held up, cut the gap to a single point with eight minutes to go.

With six minutes to go, Benson stayed calm to slot the match-winning conversion.

Another fluctuating game saw reigning champions Sale see off Newcastle at the AJ Bell Stadium.

Sale led 15-7 at half-time, after Will Haydon-Wood’s try for the Falcons was cancelled out by Arron Reed running in from halfway following a line-out.

Nathan Earle finished off a tap-penalty to bring Newcastle to within three points at 18-15 and when George McGuigan went over on 64 minutes, the visitors were ahead.

But academy graduate Rouban Birch profited from a Newcastle knock-on to dot down and sneak the Sharks back in front with eight minutes to go before Rob du Preez made sure of victory with the conversion.

Three more fixtures follow on Saturday. Gloucester host Exeter at Kingsholm, Wasps face Leicester and Bristol entertain Worcester.