"But it's going to be tough next week."
Last night's victory was laid on by two second-half goals from striker Nathan Burns who has scored 10 times this season and leads the golden boot standings after 11 rounds.
"He's really on fire and he's not only receiving good service and scoring but he's creating his own," Merrick said.
Burns, who hasn't played for the Australian national team since 2011, seems a likely bet to earn a recall to the Socceroos for next month's Asian Cup given his hot form.
If Burns was to be named in the Australian side he would likely miss the Phoenix's games against Adelaide and Brisbane next week as the Socceroos assemble to prepare for the Asian Cup.
One of the most pleasing things to come from the victory over Sydney for Merrick was the way that Wellington were able to keep a clean sheet for only the second time this season.
"We were rock solid in the first half when they needed to be because they were under the pump a little bit," Merrick said of his back four.
Goalkeeper Glen Moss also produced a couple of fine saves during the contest and showed a tough streak to play on despite copping a stray boot to the eye and cheekbone area in the second spell, which left him with a bruised face.
Left back Tom Doyle filled in for the suspended Manny Muscat and produced a sound display, while the midfield were able to gain a greater handle on proceedings in the second half, which helped Wellington earn a vital three points.
Burns scored his goals in the 73rd and 81st minutes of the game and Merrick said his fitness staff deserved praise.
"They've got the boys in great condition and I'd say we are one of the fittest teams in the league."
The upcoming stretch of games for Wellington looks imposing but it's also a chance for them to make a move up the ladder during the festive season.
"We are pretty happy with where we are at," Merrick said.
