If you want a job doing well do it yourself.

That seemed to be Chris Adams' motto at Hove last night as Sussex all but made certain that they will playing in the first division of the National League next season.

Adams scored an unbeaten 110, his first hundred in the competition for nearly two years, as Sussex opened up a ten-point lead at the top of Division Two after securing a breathless win when, with one run needed for victory, Mushtaq Ahmed carved the last ball of the match to the boundary.

The Sharks are not quite over the finishing line but their run rate is worth an extra point or two and it would take a freakish set of results elsewhere to deny them promotion, even if they were to lose their two remaining games.

The six bottles of champagne in the home dressing room suggested Sussex had a celebration in mind and a boisterous crowd of around 4,000 were certainly in party mood. A glass was no doubt raised to toast the Sussex skipper.

He came in after just four balls of the reply when Richard Montgomerie edged Azhar Mahmood to slip and could not have paced the chase any better.

A slow pitch made strokeplay difficult as a succession of batsmen down the order discovered.

Sussex lost wickets in the closing overs trying to force the pace and as the required rate grew it looked like the bubbly would stay on ice.

Surrey captain Mark Butcher saved Azhar for the last over with 11 runs needed. He won the Twenty20 meeting earlier in the season with the bat but lost his nerve this time, bowling a no ball from which two more runs were scored from the subsequent free hit and then a wide.

With six needed off three balls, Adams came down the pitch to find the vacant square leg boundary for his tenth four and took a single off the next delivery to leave Mushtaq the glory of hitting the winning runs.

Quite where he summoned the energy from is anyone's guess, but Adams embarked on what seemed to be a personal lap of honour at the end, waving his bat in the air as he acknowledged the cheers of a pumped-up crowd.

Adams said: "We're 99.9 per cent certain of promotion now so we'll probably have a little celebration tonight.

"I'm chuffed for the boys because they have worked so hard and I was delighted to get a hundred.

"I've been poor in one-day cricket this season so I owed the team a century."

Adams and Matt Prior rebuilt the innings with a stand of 90 in 15 overs for the second wicket, 40 of those runs coming between the 10th and 14th overs as Surrey's support bowlers got some stick.

Prior was leg before to off-spinner Nyan Doshi's second ball and, although Murray Goodwin helped Adams put on 60 for the third wicket, he was unable to play with his customary fluency and eventually toe-ended a pull to the mid-wicket boundary where Stuart Walters took an excellent catch as he fell backwards.

Sussex's middle order could not give Adams the support he needed but the captain stayed firm, summoning the energy to reach his hundred with an all-run four.

It was his ninth in the competition for Sussex and the one he will enjoy more than any other.

Adams was not too concerned about bowling first on a slow pitch which was used on Tuesday when his side strolled to victory against Scottish Saltires.

In the 11 one-day games where they have fielded first this season Sussex have only lost twice.

The key once again was making inroads while the ball was still hard and James Kirtley duly obliged.

If Kirtley is concerned that he may have to undergo more remedial work on his bowling action it clearly was not affecting him. He produced a peach which pitched on middle and hit off to remove James Benning and in his next over Mark Butcher obligingly picked out Goodwin on the square leg boundary.

Kirtley now has 27 wickets in the competition this season.

When Jonathan Batty reached outside off stump to give Matt Prior an easy catch Surrey were in trouble.

Mark Ramprakash and Ali Brown, however, seemed determined that the Lions, even though they had nothing to play for, would not just cave in.

Brown was his usual ebullient self, coming down the pitch and relying on a mixture of timing and his fantastic eye to hit the majority of his nine boundaries in a 42-ball cameo which ended in Mushtaq fourth over when he mis-timed an off drive to extra cover.

Mushtaq struck again in his seventh over when Ramprakash was lured down the track and although Prior did noy take the ball cleanly he still had time to whip off the bails with Ramprakash out of his ground.

At that stage Sussex must have fancied their chances of restricting Surrey to around 200.

But 96 runs came off the last 14 overs Azhar hitting 22 off 14 balls including 15 off the last over from Kirtley.

There was a testy exchange between the pair as they walked off, presumably because Azhar did not seem to be ready when Kirtley bowled the last delivery.

Four hours later his mood was to get a lot worse.