Wasps closed the gap on fifth-placed Leicester to two points after they beat London Welsh 40-13 with a bonus-point at Kassam Stadium on Sunday.
The Coventry-based outfit scored two tries in the first period – both from Tom Varndell – but they struggled to find their rhythm as the Exiles battled hard throughout.
They only went into the break 12-5 ahead following Opeti Fonua's touchdown for Welsh, but the visitors upped the intensity in the second period and secured the bonus-point through Ashley Johnson, Varndell's third score, Sailosi Tagicakibau and Alapati Leiua.
Chris Elder went over for Welsh after the interval but it proved to be mere consolation.
Dai Young's men went into the game looking to continue their push for European Champions Cup rugby next season and they opened impressively. Varndell touched down twice in the first eleven minutes and the signs appeared ominous for London Welsh, who have yet to achieve a win in the 2014/15 campaign.
However, the hosts were spirited and, after that early setback, managed to keep themselves in contention at the interval through Fonua.
It was a slack performance by Wasps but they improved in the second period and scored when Johnson finished off a dominant driving maul.
Varndell then crossed the whitewash before the Exiles hit back through Elder's excellent score.
But Young's side were obviously the more potent team with ball in hand and Tagicakibau went over with sixteen minutes remaining.
To their credit, Welsh continued to fight and had an opportunity to add to their score when Carlo Festuccia was sin-binned for the visitors.
Being down to fourteen men didn't affect Wasps, though, and Leiua completed the scoring when he touched down in the final minute.
For London Welsh:
Tries: Fonua, Elder
Tries: Varndell 3, Johnson, Tagicakibau, Leiua
Con: Goode 4, Lozowski
London Welsh: 15 Will Robinson, 14 Seb Stegmann, 13 Nic Reynolds, 12 Tom May (c), 11 Chris Elder, 10 Tristan Roberts, 9 Rob Lewis, 8 Opeti Fonua, 7 Darren Waters, 6 Pete Browne, 5 Matt Corker, 4 Ben West, 3 Ben Cooper, 2 Koree Britton, 1 Nathan Trevett.
Replacements: 16 Matthew Dobson, 17 Eddie Aholelei, 18 Jack Gilding, 19 Josh McNally, 20 Richard Thorpe, 21 Paul Rowley, 22 Olly Barkley, 23 James Lewis.
Wasps: 15 Andrea Masi, 14 Tom Varndell, 13 Elliot Daly, 12 Alapati Leiua, 11 Sailosi Tagicakibau, 10 Andy Goode, 9 Joe Simpson, 8 Guy Thompson, 7 Thomas Young, 6 James Haskell (c), 5 James Gaskell, 4 James Cannon, 3 Jake Cooper-Woolley, 2 Ashley Johnson, 1 Matt Mullan.
Replacements: 16 Carlo Festuccia, 17 Simon McIntyre, 18 Lorenzo Cittadini, 19 Kearnan Myall, 20 Sam Jones, 21 Charlie Davies, 22 Alex Lozowski, 23 James Downey.
Referee: Greg Garner
Assistant referees: Paul Dix, Peter Huckle
TMO: Graham Hughes