First Night: Downton Abbey, ITV1 (4/5), 9pm <br/>Spooks BBC1, 9pm (2/5)

The second series of Downton Abbey began with a bang – a shell exploding over a British trench as the gallant Matthew helped dimmer television viewers to understand dramatic contrast: "I think of my life at Downton and it feels like another world," he said, as the shrapnel spattered around him.

Several newspapers had suggested that 9pm last night marked the opening shot of similar attritional collision – with the first episode of the final series of Spooks going head to head against the return of ITV's country-house drama. "Clash of the Night," said the Radio Times, "Showdown!" shouted others. But, as is often the case with generals, headline writers were fighting the last war.

In an age of catch-up television and digital recorders, viewers aren't forced to choose between programmes, only which one they're going to watch first. And since Downton Abbey was longer by half an hour (leaving just enough time for Spooks to upload to iPlayer), it wasn't hard to work out which of the programmes will claim early victory when the overnights come in.

Downton Abbey had a following wind. Spooks is in its 10th series, while Downton Abbey returns to an audience still in the first flush of infatuation.

We know the characters fairly well and, after a lay-off, are eager for more. Julian Fellowes was savvy enough to ink in their profiles in this first episode, with lines reminding us of their essence. "Keeping up standards is the only way to show the Germans that they will not beat us in the end," said Mr Carson as he checked silverware. It seemed unlikely that German agents would be monitoring fish knives at Downton for signs of crumbling morale, but that's Mr Carson; the done thing is his bulwark against chaos.

Fellowes' main task was to undo some of the knots that he had tied up in the last series.

Mr Bates limped out at the station to ask Anna to marry him – a sweet pay-off of long-deferred gratification. But then his villainous wife turned up, threatening to expose Lady Mary's fatal tryst with the Turkish diplomat unless he returned to her. Naturally Mr Bates – integrity in tails – cannot tell His Lordship why he's resigned, provoking an aristocratic hissy fit: "I cannot remember being more disappointed in any man," barked Lord Grantham, faced with the appalling prospect of doing up his own buttons.

Sly Thomas, who discovered the Medical Corps wasn't the cushy number he'd hoped for, deliberately copped a Blighty by holding a lighter over the trench. One assumes he'll soon be back at Downton helping O'Brien to torment new tweenie, Ethel. I don't think fans will have felt let down.

This week, John le Carré offered a disobliging four-letter review of Spooks, beginning with "C" and ending with "p". I wouldn't go that far, but I share his bafflement at the high regard this drama enjoys, given its disregard for the realities of intelligence work.

"There's no chance of identifying him at that distance," murmurs a member of a surveillance team, as they try to work out who's killed one of Harry's former agents. Oh, you naive boy. You've forgotten the Motion Analysis Filter, which can check every pedestrian inside a mile radius in a matter of seconds.

Maddeningly Spooks isn't even true to its own account of the world, let alone the one the rest of us inhabit. At one moment, a senior Russian minister was described as virtually unfollowable because of his wily knowledge of tradecraft. At the next, one of Harry's boys was sauntering past the boot of his car to clip on a tracker, in full view of the target and his security men.

The attempts to make it topical were not too persuasive, either. "Bin Laden's death wasn't quite the panacea we'd hoped for," said the Home Secretary. If you can suspend disbelief to the point where you can imagine a senior politician saying something so ingenuous, be my guest.