The full-back's 23 points proved vital as Lawrence Dallaglio and co booked a
place in the last eight, leaving the Shoguns to concentrate on regaining their
place in the Zurich Premiership.
The visitors took an early lead as van Gisbergen converted a simple penalty
chance after the home team strayed offside but the same offence by the Londoners
allowed fly-half Jason Strange to level the scores.
Wasps were also first to score a try as Alistair McKenzie was tackled but
managed to pop the ball up for scrum-half Harvey Biljon, who raced in from the
22 to touch down with van Gisbergen adding the extras.
Strange was short and wide with his second penalty attempt, this time from 40
metres, before a fight broke out as the scrum broke up and referee Tony
Spreadbury sent Wasps' tighthead prop Henry Nwume for a 10-minute cooling-off
spell in the sin-bin.
Bristol failed to take advantage of the extra man but the crowd erupted on the
half-hour when lock Ollie Hodge took the ball at a 22 metre lineout, fed skipper
Darren Crompton and on to number eight Jim Brownrigg who sold a neat dummy and
then used his height to stretch for the line.
Strange added the extras to level the scores but that parity was short-lived.
Strange failed to find touch, centre Rob Hoadley mounted an attack and slipped
the ball to wing Josh Lewsey for the England international to outpace flanker
Chris Morgan and touch down against his former club.
Van Gisbergen added the conversion from out wide and that of Wasps' third try
from wing Tom Voyce, after captain Dallaglio and hooker Ben Gotting had linked
up. Strange was off-target with another penalty attempt before finding his mark
just before the interval as Bristol trailed 13-24 at the break.
The Shoguns scored two tries in the quarter after the break, though the
players and crowd thought it was three. Strange had a kick charged down but it
went straight into the arms of centre Rob Higgitt to race through from 15 metres
followed by full-back Bernardo Stortoni from 35 metres.
Strange converted both, either side of van Gisbergen scoring a penalty, but
referee Spreadbury denied centre Sam Cox the third for a knock on after Stortoni
had intercepted on his own 22. Wasps then applied the pressure but Bristol
mounted a solid defence.
Bristol went into the lead for the first time in the game on 67 minutes, as
Strange kept his cool to land his third penalty, only for van Gisbergen to
cancel it out from 40 metres out and then restore the lead with his fourth five
minutes from full-time.
The scores remained unchanged for the opening 10 minutes of added time before
van Gisbergen landed his fifth penalty from the right touchline to give the
visitors the edge.
Wasps sealed the game five minutes from time as flanker Tom Rees ran in from
22 metres to score under the posts and van Gisbergen converted to shatter
Bristol's dreams.
Teams
Bristol: Stortoni, Marsden, R. Higgitt, Cox, Nabaro, Strange,
Blake, Hilton, Nelson, Crompton, Kohn, Hodge, Pearce, Morgan,
Brownrigg.
Replacements: Billig for Cox (89), A. Clarke for Hilton (67),
N. Clarke for Nelson (67).
Not Used: Nicholls, Pritchard, Fox, Bignell.
Tries: Brownrigg, R. Higgitt, Stortoni.
Cons: Strange 3.
Pens: Strange 4.
Wasps: van Gisbergen, Lewsey, Abbott, Hoadley, Voyce, Brooks,
Biljon, Mackenzie, Gotting, Nwume, Hart, Skivington, Dallaglio,
Rees, Haskell.
Replacements: Richards for Abbott (26),
Cipriani for Biljon (99), Barratt for Gotting (68),
Green for Nwume (85), Birkett for Skivington (53).
Not Used: Chamberlain, Priscott.
Tries: Mackenzie, Lewsey, Voyce, Rees.
Cons: van Gisbergen 4. Pens: van Gisbergen 5.
Sin Bin: Nwume (16).
After Extra Time
Att: 9,532
Ref: T Spreadbury (England).