Pietersen heroics not enough for Hawks
England's Kevin Pietersen took three wickets and top scored for Hampshire on his Twenty20 Cup debut at the Rose Bowl but still finished on the losing side.
The Hawks finished on 157 for eight in pursuit of a victory target of 191 despite Pietersen's earlier heroics.
The man at the centre of Middlesex's 33-run victory was all-rounder Shaun Udal, returning to the club he served for 20 years for the first time.
Udal hit three sixes in a brisk innings of 32no and then strangled Hampshire in mid-innings with a spell of three for 21 from his four-over allotment.
Udal's dismissal of Pietersen to a catch at backward point by Murali Kartik proved to be the turning point of the match.
Two balls later, Udal dismissed Sean Ervine to a leg before decision and from that position Hampshire never recovered.
Pietersen coming in at three, put on 74 in only seven overs for the fourth Hampshire wicket but with their double dismissal, Hampshire were never again a threat in front of a crowd of around 6,000.
Earlier, Middlesex, having been put in, raced to 190 for seven with lively contributions at the top of the order from Andrew Strauss, Ed Smith, Owais Shah and Ed Joyce.
Joyce hit two sixes in his 34 but Shah was his side's top scorer with five boundaries in his 48.
Then Udal arrived to a rousing reception from his former supporters, to ensure that Hampshire were left with a stiff target.
Pietersen bowled three overs and finished with three for 33, dismissing Shah, Joyce and then Tim Murtagh to an outstanding catch off his own bowling running backwards towards mid-on.
But Hampshire made a disappointing response even when Pietersen was in full flow.
Pietersen hit a six off Kartik and six fours from 29 balls and all the while Ervine, who made 31, was at the crease with him, Hampshire stood a chance.
But Udal and Kartik put the brakes on the scoring and wickets tumbled in an attempt to accelerate.
Udal said: "It was nice to get the chance to show a few people I can still play. I got lucky today and I was pleased with the way the fans here gave me such a good response."
Udal, now 39, was not given a new contract at the end of last season and joins Middlesex on a two-year contract.