An excellent defensive display from Harlequins earned the visitors a 23-16 victory over Leicester Tigers at Welford Road.
Quins dominated much of the first half and, despite playing against the wind, they impressively went into the break with a 10-6 advantage through Nick Easter's converted try and Evans' penalty.
The Tigers had initially taken a 6-0 lead through two Owen Williams three-pointers but they were outplayed in the opening period.
They also had no answer to the vibrant visitors in the second half and, despite a third Williams' penalty, Matt Hopper's touchdown and the boot of Evans sealed the win, although a late penalty try restored some pride for Leicester.
Against a strong gale, the London-based outfit looked to move the ball through the phases. It was a tactic that proved fruitful with their powerful forwards regularly making yardage, but they couldn't make the possession and territory count due to handling errors.
In addition, Conor O'Shea's men were struggling with the hosts' destructive scrum and, from a set-piece infringement, Williams took Leicester into the lead.
The fly-half then added his second from the tee as they went 6-0 ahead with 19 minutes of the game gone. But the visitors persisted with their off-loading style and it eventually paid dividends when Evans scored their first points of the evening with a penalty.
With the pressure increasing on the home side's rearguard, Julian Salvi received a yellow card and Easter powered over from close range as Quins went into the break with a 10-6 advantage.
Leicester were looking for a reversal of fortunes after the interval, but they came up against a side that continued to play the same fluent rugby.
Hopper went over in the 44th minute when Luke Wallace's pass gave the centre the space, and he stepped inside the cover defence for a superb score.
Williams reduced the arrears to eight points but successive Evans three-pointers effectively sealed a mightily impressive win, although a penalty try gave the Tigers a losing bonus-point.
Pens: Williams 3
Yellow Card: Salvi
Tries: Easter, Hopper
Cons: Evans 3
Pens: Evans 2
Leicester: 15 Niall Morris, 14 Scott Hamilton, 13 Terrence Hepetema, 12 Dan Bowden, 11 Adam Thompstone, 10 Owen Williams, 9 David MÃ©lÃ©, 8 Jordan Crane, 7 Julian Salvi, 6 Ed Slater, 5 Graham Kitchener, 4 Louis Deacon (c), 3 Logovi'i Mulipola, 2 Neil Briggs, 1 Marcos Ayerza.
Replacements: 16 George Chuter, 17 Boris Stankovich, 18 Fraser Balmain, 19 Steve Mafi, 20 Thomas Waldrom, 21 Sam Harrison, 22 Matt Smith, 23 Blaine Scully.
Harlequins: 15 Nick Evans, 14 Charlie Walker, 13 Matt Hopper, 12 Tim Molenaar, 11 Ugo Monye, 10 Ben Botica, 9 Danny Care, 8 Tom Guest, 7 Luke Wallace, 6 Joe Trayfoot, 5 George Robson, 4 Nick Easter (capt), 3 Will Collier, 2 Dave Ward, 1 Mark Lambert.
Replacements: 16 Harry Allen, 17 Darryl Marfo, 18 Nic Mayhew 19 Charlie Matthews, 20 Jack Clifford, 21 Karl Dickson, 22 Tom Casson, 23 Sam Smith.
Referee: Tim Wigglesworth
Assistant referees: Greg Garner and Kevin Stewart
TMO: David Grashoff