West Ham manager Manuel Pellegrini urged fans to "trust" the team after the Hammers threw away a lead and lost at home to Bournemouth - their second loss in two games this season.

A fine individual goal from Callum Wilson and a Steve Cook header six minutes later gave Bournemouth the win after Marko Arnautovic's penalty had put the hosts ahead in the first half.

Pellegrini, who won the Premier League title with Manchester City in 2013-14, replaced former boss David Moyes in the summer after he was not given a contract extension having only finished 13th.

West Ham fans repeatedly protested during last season and, although there were no protests on Saturday, a large number of the 56,888 crowd at London Stadium did leave early.

"The fans must also trust again this season," said Pellegrini. "The stadium was empty with 10 minutes to go, we can still score in that time. They need to believe but if you don't have results it is more difficult for them.

"The squad, everyone, must forget about last season, trust what we are doing and look to the future.

"I feel the squad is without trust, many have to adapt to the Premier League. We knew we had a difficult start with our fixtures but at home we must win."

The Hammers, beaten 4-0 at Liverpool last Sunday, took the lead when Arnautovic converted a penalty after Javier Hernandez had been clipped by Nathan Ake.

But Wilson equalised as he ran with the ball from near the halfway line and slotted past Lukasz Fabianski, before defender Cook secured a fine away win from Ryan Fraser's free-kick.

It means West Ham have failed to earn a point from Pellegrini's first two games in charge, while Eddie Howe's Bournemouth have two wins from two matches.

During the summer Pellegrini signed nine new players, spending almost ￡100m in the transfer market, but his side have now played two, lost two, only scored once and have conceded six times to sit bottom of the table.

Their Chilean manager named an attacking line-up, with Javier Hernandez, Felipe Anderson, Arnautovic and Robert Snodgrass all in the side, but, just like last season, the Hammers' defensive frailties again showed.

When it was goalless, a poor West Ham offside trap failed and that enabled Wilson to shoot at goal, but he was only denied by excellent reflexes by Fabianski, who got down quickly to save it.

The hosts actually took the lead a minute later with Arnautovic's well-taken penalty after Ake had slid in on Hernandez and caught his standing foot.

However, West Ham were given another scare just before half-time when David Brooks again avoided the offside trap, but wasted the chance, glancing a free header wide.

Brooks, a summer signing from Sheffield United, nearly equalised at the start of the second half but was only denied by another one-handed save by Fabianski.

However, Wilson's fine individual goal and Cook's header left West Ham fans frustrated. It could still get worse for the Hammers as they have a tough run of fixtures, including matches against Arsenal, Everton, Chelsea, Manchester United and Tottenham in five of their next seven games.

"The team was too nervous," added Pellegrini. "We won the first half 1-0, from the bench it looked like the players wanted to finish and didn't continue playing, especially late in the first half. In the second half we conceded two easy goals, four defenders against one for the first goal."

There looked to be little danger when Wilson picked up the ball in the 60th minute, as he was the only Bournemouth man in the West Ham half.

But, with the home defence backing off, Wilson was able to run at them, avoid a half-hearted challenge from Fabian Balbuena, skip past a sliding tackle from Pablo Zabaleta and calmly slot past Fabianski.

That is two goals in two games for Wilson as he also scored in Bournemouth's 2-0 win over Cardiff in the opening weekend of the season.

His team went ahead six minutes later when Cook was too strong for his marker Angelo Ogbonna, who had needlessly given away a free-kick on the side of the penalty area with a clumsy foul on Fraser.

West Ham brought on Carlos Sanchez and Lucas Perez late on, with both summer signings making their debuts as the Hammers pushed for an equaliser.

But the hosts did not manage to create much after that moment, apart from a Jack Wilshere shot that was comfortably saved by Asmir Begovic, who also produced a fine save in the first half to deny Hernandez when it was goalless.

Bournemouth were even able to leave out club record signing Jefferson Lerma, the Colombia midfielder who they signed for ￡25m from Levante, and did not need to bring on Jermain Defoe against the club where he started his career.

For the Cherries, they now have six points from two matches and it is a complete contrast to last season, when they lost their opening four league matches.

Bournemouth manager Eddie Howe told BBC Sport:

"It was an excellent win and an excellent performance, especially the second half. At 1-0 down, there's a lot of work to do so credit to the players.

"Every team is reliant on their creative players and all those for us functioned well in the second half. How we haven't scored more we will have a look back, but it is a good sign.

On Wilson's goal: "We really needed it, a really good goal. He is outnumbered and showed his pace and it was a really good finish. Hopefully this is the start he needs to believe he can have a good season - we know he is capable."

An away trip to Arsenal is next for West Ham, on Saturday, 25 August (15:00 BST), while Bournemouth will be playing at home to Everton at the same time.