HEERENVEEN, Netherlands (Interstat) — In a stunning opening-day upset, Heerenveen defied heavy pregame projections to defeat AZ 3-1 in an Eredivisie match Sunday at Abe Lenstra Stadion.

The result flipped the script on statistical models, which heavily favored the visiting side. Interstat’s game simulator had projected a 2-1 victory for AZ, while its ELO system gave AZ a 72.7 percent probability of winning.

Heerenveen’s victory was fueled by a rapid-fire pair of first-half goals and a resilient performance after AZ clawed one back in the second half. The win gives Heerenveen a perfect start to their domestic campaign, moving their Eredivisie record to one win and no losses. AZ begins its season with a record of no wins and one loss.

The home side struck first in the 38th minute. Forward Dylan Vente opened the scoring, finding the net to give Heerenveen an early lead and energize the home crowd.

The advantage was doubled just two minutes later in a devastating blow to AZ. Midfielder Joris van Overeem equalized for the visitors, slotting a shot past the Heerenveen goalkeeper to make it 1-1 in the 40th minute.

The match settled into a stalemate until the final quarter-hour, when a pair of substitutes made a decisive impact. In the 75th minute, Troy Parrott, who had entered the game off the bench, restored Heerenveen’s lead with a crucial goal to make it 2-1.

The home team sealed the victory just four minutes later. Midfielder Luuk Brouwers netted in the 79th minute, securing the three points for Heerenveen and capping the 3-1 triumph. Defender Sam Kersten was credited with an assist on one of Heerenveen’s goals.

The only blemish for the winning side was a yellow card shown to Kersten in the 54th minute.

The match was the first of the Eredivisie season for both clubs. Heerenveen’s record across all competitions now stands at one win and no losses, while AZ’s overall record falls to no wins and one loss.