Hampshire 285 (Wheater 57, Berg 54, Rankin 3-55, Clarke 3-66) and 82 for 1 lead Warwickshire 125 (Edwards 5-32, Crane 5-35) by 242 runs
Mason Crane bamboozled Warwickshire to become the youngest Hampshire player to take a County Championship five wicket haul on Day Two at the Ageas Bowl.
Leg spinner Crane, who is 18 and 171 days, beat Alex Kennedy's 106-year record by 21 days as he posted figures of 5 for 35. This is only his second first-class match after making his debut against Durham last month.
He shared the Hampshire wickets with West Indian Fidel Edwards who also returned a five wicket haul with marginally better figures of five for 32.
It wasn't all plain sailing for Crane as he dropped a basic chance at mid-on to give Laurie Evans a life - off Jackson Bird, who was bitterly unlucky to go wicketless.
The 18-year-old Crane began his wicket taking spell by bowling Warwickshire captain Varun Chopra with a well disguised googly.
Then four balls latter Crane added another former Test star to his scalp list - his first professional wicket was Kumar Sangakkara - as Jonathan Trott scored a second duck in a week against Hampshire.
Sam Hain and Tim Ambrose then departed in two balls to leave Crane on a hat trick - Hain caught behind while wicketkeeper Ambrose was leg before - to end a 20 ball spell of four wickets for six runs.
West Indian Fidel Edwards had taken the first Warwickshire wicket before lunch when Ian Westwood edged to Gareth Berg at fourth slip.
He then took over from his accomplice Crane to clean up the tail with his speedy and slingy action.
Rikki Clarke was struck on the pads leaving to depart lbw, then to the last ball of the afternoon Chris Woakes edged behind.
Edwards and Crane sharing all ten Warwickshire scalps, with the away side losing their last nine wickets for just 47 runs.
Hampshire had 26 overs to boost their 160 run lead - after deciding against forcing the visitors to follow-on. But they lost Jimmy Adams in the fourth over as he top edged a hook to Westwood at square leg.
Michael Carberry got away with a voracious caught behind appeal early on but reached 34 at the close - with captain James Vince also on 34 and the Hampshire lead up to 242.
In the morning, seamer Clarke saw off the stubborn Hampshire tail to bowl the hosts out for 285, after Gareth Berg scored his fourth fifty of the summer.
Italian international all-rounder Berg collected his 73 ball half century with a boundary - which also brought up the 50 partnership with Mason Crane - to continue his fine summer with both bat and ball following his winter move from Middlesex.
Berg only managed eight more deliveries before he mistimed a pull shot to Boyd Rankin at fine leg - soon after changing his bat - to give Clarke his second of the innings.
And the ex-England Test bowler finished the home side with his third scalp when Crane prodded a short delivery to Trott at leg slip - scoring a sedate 13 from 68 balls.
West Indian Fidel Edwards was the unbeaten batsman, scoring an exciting 17 - as the hosts missed out on a third bonus point by 15 runs.