'Luck's definitely not on our side', says Manchester United boss Ten Hag after West Ham loss
United slipped to 14th in the Premier League table after Jarrod Bowen's controversial stoppage time penalty winner handed the Hammers all three points.
Crysencio Summerville put West Ham in front against the run of play 16 minutes from time before Casemiro equalised.
Ten Hag was furious at the award of the spot-kick after VAR intervened when Matthijs de Ligt clashed with Danny Ings inside the box.
United captain Bruno Fernandes had a red card rescinded after being sent-off in a 3-0 defeat by Tottenham last month and Ten Hag highlighted the inconsistency of when VAR decides to challenge the referee's on-field decision.
"Before the season they explained the process of VAR - only when (it is) clear and obvious they should interfere," said Ten Hag.
"What they didn't do against Spurs, that was a wrong decision. Now they make a wrong decision interfering and both have big impact on the games. I don't criticise the personnel, I criticise the process."
However, it was a familiar lack of wastefulness in front of goal that cost United a much-needed victory.
Diogo Dalot missed an open goal, while Alejandro Garnacho and Fernandes were also guilty of missing huge chances in a dominant first-half display.
"We created so many chances, played so good football, especially in the first half. How I want my team to play in and out of possession," added Ten Hag.
"Six or seven 100 per cent chances we should have scored. That is a point of improvement. But overall I had not so many criticisms of my team, apart from not scoring."
United's return of eight goals from their first nine games is their worst in the Premier League era.
Ten Hag's men have won just three of those matches and drawn all three of their opening games in the Europa League to leave their manager clinging on to his job.
But he claimed to have seen positive signs in a 2-1 win over Brentford last weekend and a 1-1 draw at Fenerbahce prior to their visit to the London Stadium.
"At this moment the luck is definitely not on our side. Last season was not different and near the end we turned it around," said Ten Hag.
"We are so determined it will be the same (this season). We have to turn this around and it will turn around if we keep playing like we are now.
"Brentford, Fenerbahce, today, we played really good football."