Parramatta overturned an imposing half-time deficit to triumph 28-20 over the Bulldogs in their opening round NRL match at Sydney's Olympic stadium this evening.

The Bulldogs blew the Eels off the park in the first 40 minutes, scoring 20 points without reply through tries from Lee Te Maari, Willie Tonga and Hazem El Masri.

But a Brett Finch-inspired Parramatta fight-back produced 28 unanswered points in the second half, with a brace of tries from Joel Reddy and Feleti Mateo in addition to an Eric Grothe Jnr four-pointer.

Full-back Luke Burt levelled four conversions from five attempts, gifting Michael Hagan's side a miraculous comeback win against their historic rivals.

Hagan says he did not have to say too much to his players at the break.

"The players knew that we weren't playing well and there were a couple of key areas we needed to improve on to stay in the game and to come away with a win," he said.

"We can think ourselves reasonably lucky to give a quality team like Canterbury a 20-point start and still come out in front."

A slick attacking display got the Bulldogs off to a flying start, with five-eighth Ben Roberts showing great skill with ball in hand to set up consecutive tries for Te Maari and Tonga.

Daniel Holdsworth put El Masri over in the corner, who contributed three conversions and a penalty goal from the boot to register his 600th career point at the Homebush venue.

Hagan appeared visibly stunned in the grandstands, and his half-time talk certainly had the desired effect as the Eels returned to field with renewed energy.

Finch had his hand in just about everything in the second half, producing a fine chip kick to pick out Grothe on the wing early which kick-started the fight-back.

The former Raiders and Roosters half-back also showcased his ability to run at players, sending Mateo over with a sweetly timed off-load after making the decision to run early in the set.

Finch then produced another sublime cross-field effort off the boot for Reddy to out-leap Bulldogs opposite Matthew Utai and ground the ball.

Mateo then came to the party with a brilliant flick pass to workhorse back rower Nathan Hindmarsh, who fed the ball through the hands for Reddy to grab his second on the right flank.

Hindmarsh's defensive effort was the equal of Finch's attacking performance, with two desperation touches to clear the ball in-goal either side of the break preventing further scoring opportunities for the Bulldogs.

With the scores at 22-20 in the final four minutes the Bulldogs had the chance to apply pressure in their attacking 20 metres zone, but when new recruit Michael Sullivan picked out Reddy with an errant blind pass the contest was as good as over.

Mateo completed his double and a stunning Parramatta turnaround with buzzer-beating try, leaving the Bulldogs to reflect on a horrendous second-half capitulation.

Parramatta: 28 (J Reddy 2, F Mateo 2, E Grothe Jnr tries; L Burt 4 conversions)

Bulldogs: 20 (L Te Maari, W Tonga, H El Masri tries; El Masri 3 conversions, penalty goal)