Ten years to the day since Exeter made their Premiership bow and it is a measure of just how far they have come that their march towards a fifth straight final looks unstoppable. Again they fielded their second team but again they had too much for one of the more fancied sides in the league before the restart – Tom O’Flaherty coming up with a crucial try in the last 10 minutes. In many ways it was not a vintage Exeter performance, they did not dominate possession nor territory in the manner they tend to, but in another it was. Rob Baxter has cultivated a side who know precisely how to win. He has them so well drilled it seems not to matter whether it is the first-choice XV who ripped Worcester to shreds last time out, or the reserves who downed Bristol on their own patch. Don Armand does not make Baxter’s first team these days but it was he who came up with the crucial intervention at the end to ensure victory. Gareth Steenson and Phil Dollman both play bit-part roles too but here they were the two surviving starters from that 22-10 win over Gloucester in 2010. “If you talk through the seasons one at a time, the big games we’ve lost and the games we’d have liked to have won, the heartache times and the joyful times, it does feel like it’s been 10 years in the making,” Baxter said. “All we’re trying to do is stay consistent and that’s paying off.” You have to feel for Northampton, who showed considerable character – Dan Biggar in particular – to lead by two points before O’Flaherty’s try but nonetheless this was a fifth straight home defeat in the Premiership. Chris Boyd had warned beforehand that defeat would mean their No 1 priority would become the European Champions Cup. The bad news is the tie is at Exeter. “Three of the [top] four have always been pretty obvious and we have too much work now,” Boyd said. “We haven’t stopped trying but sometimes you can’t win a trick. We made three mistakes that cost us three tries.” For a team who had lost three of their past four games, Northampton did not begin with the kind of intent Boyd would have wanted. They were rushed in possession and, more significantly, rancid in defence. Exeter had two tries in the first 12 minutes, each well worked, with the Chiefs, as is their way, going through plenty of phases to eventually create an opening. Sean Lonsdale will have few easier finishes than his side’s first, ghosting through a huge gap with Henry Taylor and George Furbank both at fault. Jannes Kirsten was soon following him over, taking Alec Hepburn’s inside pass and running under the posts unopposed. Northampton did not buckle and Biggar must take plenty of credit for that. Teimana Harrison is the Northampton captain but there is only one voice audible from under the posts. The Wales fly-half was demanding more effort from his side and they certainly showed that in stringing 25 phases together in and around the Exeter 22, only for Tomas Francis to come up with the crucial turnover. Undeterred, Saints kept coming and after another siege to the Exeter line, David Ribbans went over and they had their second when James Fish slipped through the Exeter defence and found Taylor in support. It was a move orchestrated by Biggar – the only surprise that he missed the conversion which would have taken Northampton in level at the break. Less than two minutes after the restart, Northampton were over again. Rory Hutchinson arced his way down the right, then in field and offloaded to Biggar. He didn’t quite back himself but after the ball was swiftly recycled, Ribbans was able to reach out and dot down for his second. Exeter by this stage found opportunities to venture into Northampton territory a rarity but on one of the few occasions O’Flaherty made ground down the right, Steenson reduced the deficit to just two points from in front of the posts. When Exeter were awarded a penalty on halfway with 10 minutes to go it looked ominous for Saints and a driving lineout took the Chiefs close before O’Flaherty bundled over in the corner.