Jordan Brown was left with mixed emotions on Monday afternoon after netting twice in a 5-3 defeat against his former club Arsenal at London Colney.
The forward impressed on his first start in the Barclays Under-21 Premier League, grabbing two of the Hammers' goals alongside an overhead kick from Dan Potts.
Zak Ansah and Chuba Akpom struck two late goals to see off the Hammers, and Brown admitted that losing late in the day had took the shine off his first goals for the Development Squad.
He told West Ham TV: "I was quite happy to score as it's always nice to score, especially against my old club.
"I was very happy, but at 3-3 it was there for us to go and win the game so I was disappointed that we didn't get anything from the match.
"It means a lot, it means a hell of a lot actually, to score against my old club. It's all about the result in the end and I'd rather have not scored if it meant we'd have won the game."
The young Hammers fell behind three times and equalised three times, with Potts' third leveller coming just ten minutes before full-time.
Arsenal then struck twice in the following five minutes to sink the visitors, and Brown felt the game was there to be won for the Hammers.
"Straight after the game we felt a bit deflated because it was there for us on Monday. We equalised three times and the game was there for us to take but unfortunately it didn't work out that way.
"We had the momentum and it was all in our hands to go for it, but sometimes a bit of complacency will cost you in a football match at this level."
The 17-year-old striker, who signed from the Gunners last summer, filled the void left by top-scorer Elliot Lee's injury superbly with two strikes that any frontman would be proud of.
His first goal was a well-struck shot from the edge of the area which nestled in the bottom corner, while his second owed much to his poachers' instinct, as he was in the right place at the right time to turn Blair Turgott's cross into the net.
The pacey forward might have bagged himself a hat-trick had a glancing header from a corner nestled in the net, rather than rebounding off the post, the small margins of which left Brown frustrated.
"It hit the post and those little things matter. If that goes in then we could have gone in to win the game. I'm quite content with my first league start for the U21s but I still have improvements to make."
Brown will have another chance to impress on Friday night, when the Development Squad play Middlesbrough at the Boleyn Ground and Brown is eager to play at the Club's stadium for the first time.
"We've got a few injuries at the moment so I've got to take the opportunity when it comes my way.
"I've never played at the Boleyn Ground before, so I'm really excited to play there and turn over this result.
"It's a good motivation, we've got a young team right now and I think us doing well in the U18s gives us that bit more confidence at this level. Under-21 football is new to a few of us, and it's a new step which is exciting for us."