Harlequins moved back to the top of the Premiership standings on Sunday thanks to a hard-fought 31-26 win over London Welsh at Kassam Stadium.
The result sees Quins move two points clear of second-placed Saracens.
The game went according to the form book in Oxford and the visitors were halfway towards the try bonus point within the opening 20 minutes but Welsh rallied in the second half and gave the reigning champions quite a scare.
Danny Care got the ball rolling after quarter of an hour with a typically quick and incisive snipe and that was followed soon afterwards by a try for George Lowe, who exploited some soft defence from the hosts.
London Welsh weren't helped by a yellow card for Kirill Kulemin for a high tackle on Ollie Lindsay-Hague midway through the half either and Chris Robshaw added a third try for Quins just before the break.
Gordon Ross did get the home side on the scoreboard with two penalties towards the end of the first half and a further six points after the interval though and, after Adam Balding was held up with the try-line at his mercy, they finally got the try they were searching for just after the hour mark.
Nick Scott finished off a good passage of play, which included a strong burst from centre Seb Jewell in the build-up, and all of a sudden the result looked far from a foregone conclusion.
Harlequins responded like champions though as Nick Evans sealed the bonus point several minutes later, rounding off the kind of flowing move that they have made their trademark in the past year or two.
Ed Jackson did intercept a loose pass and sprinted away for a second try for the exiles late on to set up a tense and frantic final 10 minutes.
However, after George Robson and James Tideswell were both sent to the sin bin for being a little over-exuberant off the ball, neither side was able to add to their points total.
Both sides will be relatively content with the result though, with London Welsh happy to have rescued what could be a vital losing bonus point when it comes to the final reckoning after being 21-3 down at one stage and Quins walking away with the maximum haul of five points and climbing back to the league's summit.
For London Welsh:
Tries: Scott, Jackson
Cons: Ross 2
Pens: Ross 4
Yellow cards: Kulemin, Tideswell
Tries: Care, Lowe, Robshaw, Evans
Cons: Evans 4
Yellow cards: Robson
London Welsh: 15 Tom Arscott, 14 Dan Caprice, 13 Seb Jewell, 12 Sonny Parker, 11 Nick Scott, 10 Gordon Ross, 9 Rob Lewis, 8 Adam Balding, 7 Michael Hills, 6 Ed Jackson, 5 Kirill Kulemin, 4 Jonathon Mills (c), 3 Paulica Ion, 2 Neil Briggs, 1 Frank Montanella.
Replacements: 16 Greg Bateman, 17 Tom Bristow, 18 James Tideswell, 19 Matt Corker, 20 Alfie To'oala, 21 Tyson Keates, 22 Alex Davies, 23 Tom Voyce.
Harlequins: 15 Ollie Lindsay-Hague, 14 Tom Williams, 13 George Lowe, 12 Jordan Turner-Hall, 11 Sam Smith, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw (c), 6 Tom Guest, 5 George Robson, 4 Charlie Matthews, 3 James Johnston, 2 Joe Gray, 1 Joe Marler.
Replacements: 16 Rob Buchanan, 17 Mark Lambert, 18 Will Collier, 19 Sam Twomey, 20 Luke Wallace, 21 Karl Dickson, 22 Ben Botica, 23 Matt Hopper.
Venue: Kassam Stadium
Referee: Llyr Ap Geraint-Roberts
Assistant referees: Paul Dix, Robin Goodliffe