Opening batsman Walker notched 125 after spending 46 overs at the crease, helping his side set a target of 288 for seven.
The opener eventually holed out at deep on as tiredness set in.
Walker was delighted to make a winning startthe Southern League premier division season as Havant look to launch a challenge to South Wilts superiority in recent years.
‘It is great to get up and running with a maximum points haul,’ he said.
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‘On a really good wicket and with the sun shining we posted an impressive total.
‘It is good to set down an early marker and all our top five batsmen possess the talent to make big scores.’
In the middle order, Chris Stone hit a quick aggressive 30 runs to change the momentum further in Havant’s favour.
Towards the end of the innings, Richard Hindley used all his experience to notch a useful 50 not out.
In reply, Alton looked as though they might threaten when they reached 130 for four but the visitors nicked a couple more wickets to regain the initiative.
‘We took wickets at important times and controlled affairs,’ said Walker.
Aussie Tom Vanderslik took three for 28 bowling 10 overs on the bounce at the back end of the Alton innings.
Hindley and Stevie Matthews also helped break up their innings as the slow left arm spinners worked well in tandem.
Joe Collings-Wells (66) and Geoff Dods (72) laid the foundations as Burridge opened up with a 24-run win over Hampshire Academy.
Burridge reached 235 for eight before the Academy were reined in by a fine spell of bowling from Dan Stancliffe (five for 31).
Ventnor were overpowered by champions South Wilts at Steephill despite a battling innings by Hugh Calloway (42).
The hosts were bowled out for 188 chasing a target of 271 for nine.