Somerset 134 and 396 for 5 (Hildreth 101*, Trego 89*, Trescothick 71, Suppiah 70) beat Sussex 221 (Joyce 65) and 308 (Nash 126, Goodwin 77, Thomas 5-68) by five wickets

Only once have Somerset pulled off a fourth-innings run chase of greater magnitude than this and Yorkshire still shudder at its memory. Sussex will feel similarly shaken after Somerset surged to a five-wicket victory which gives them the opportunity to steal the runners-up position in Division One at the last.

Peter Trego at his belligerent best, alongside a suave unbeaten century by James Hildreth, completed an outstanding win, which took them one point clear of Sussex, who must feel mugged. Warwickshire might have secured the title but the runners-up position will now not be settled until the final day of the season.

When Trego flicked Steve Magoffin, Sussex's one bowler of real threat, through square leg for four Somerset had overhauled a target outdone in magnitude only by their successful fourth-innings chase of 479 for 6 against Yorkshire at Taunton in 2009.

The loss of four quick wickets at the fag end of the third day had seemed likely to cost Somerset dearly, but Hildreth, who finished unbeaten on 101 from 180 balls, steadied matters on the final morning with Alex Barrow and then was content to tick along as Trego took command. Their partnership rattled along at more than six an over - 166 from 25 overs - and victory came with 40 overs to spare.

Trego finished unbeaten on 89 from 72 balls with 12 fours and four sixes. He is so consumed by attacking presence that bowlers can lose heart at the mere sight of him. He is surely unfortunate that England never give him a second thought in Twenty20. He could not be more dismissive of his chances. "There is more chance of me growing a second winkie," he said.

Trego destroyed a poor spell from James Anyon after lunch, helping himself to four boundaries in two overs from the bowler. The last was a rank long hop that he pulled for four and the previous deliveries were not much better. Three slog-sweeps for six against Sussex's spinners - the first against Monty Panesar which took him to 50, the last two against Chris Nash - took Somerset within range. Even Magoffin was despatched over the ropes. Hildreth ticked off his hundred in the nick of time.

Hildreth's most fortunate moment was on 28 when he inside-edged Nash but the wicketkeeper, Ben Brown, failed to make contact. But, on this occasion at least, the Sussex bowling attack consisted of Magoffin and ragamuffins.

Magoffin took Sussex's only wicket of the final day. Hildreth and Barrow had taken their partnership to 80 in 32.2 overs when Magoffin, with the new ball only five deliveries old, found the penetration to have Barrow caught at first slip. But the wicket soon looked flat again, there was no swing under idyllic blue skies and Somerset reassumed control.

Barrow walked off slowly, his dejection apparent. He is only 20 and had looked composed for his 40. But you are not really a man until you have seen off the likes of Magoffin with a hard ball in hand.

"Where would we be without Magoffin?" asked a Sussex supporter at the deckchair end as the Queenslander struck. It turned out to be a rhetorical question. "I'll tell you where we'd be. We'd be down the bottom with Worcestershire and Lancashire, that's where we'd be."

Magoffin would be a contender for a Division One team of the season. Only a small handful of bowlers have taken more Division One wickets this season at lower cost than his 54 at 19.29. But the talk at the end was of Hildreth and Trego and, as so often in Somerset cricket, it was happy talk.

It has been a tough season for Somerset, with lots demanded of promising young players before their time. They have held together magnificently. Brian Rose, their outgoing director of cricket, might not be dreaming of another runners-up trophy, but they aim to give him one all the same, and celebrate his departure in style.

David Hopps is the UK editor of ESPNcricinfo