Palace slipped to a narrow defeat at Selhurst Park as Marvin Emnes' clinical finish proved the difference in a hotly-contested match.
Dougie Freedman made just one change to the side that took on Leeds last weekend, with Darren Ambrose replacing Wilfried Zaha.
Palace skipper Paddy McCarthy was the first to go close from an Ambrose free-kick, won by the lively Sean Scannell on the right. Then Jermaine Easter fired off a rocket of a strike from 20 yards that Boro keeper Carl Ikeme had to be alert to tip over, with the visitors playing their part in the game as they looked dangerous on the break early on.
Easter continued to look bright, first playing Scannell through, only for the Boro captain Matthew Bates to recover well, and then getting to the by-line and pulling back a decent cross that the visitors had to be alert to clear.
Boro started to take charge though and Justin Hoyte broke down the right, putting in a good cross that both McCarthy and Tunchev had to be alert to deal with, the former heading clear and the latter blocking the rebound.
As the rain poured down in south London the game became slightly more attritional, with both defences on top as the game passed the half-hour mark. Sean Scannell's deflected strike nearly fell for Easter but Boro remained on top as the game reached half-time, despite not having created a chance of note.
The second half continued in a similar pattern, with Boro enjoying large swathes of possession and Palace looked dangerous on the break but neither side created anything of note in the first twenty minutes.
Then the visitors took the lead, Barry Robson's cross from the left coming off Paddy McCarthy's head and reaching Emnes at the back post. The in-form striker made no mistake, hammering home past Speroni on the half-volley. Dougie Freedman reacted immediately and sent on Wilfried Zaha and Glenn Murray for Ambrose and Jonathan Parr, and the young winger showed his class immediately with a run down the right that saw him beat two men before slamming a shot into the side-netting.
Zaha then drew a foul from Joe Bennett, and with the full-back already booked the visitors were down to ten men. From the resulting free-kick Murray rose highest and met the ball firmly but couldn't keep his header down.
Zaha beat his men out wide twice more in quick succession, first finding Scannell who couldn't keep his shot on target and then, as the game entered the final stages, Easter, who slammed his shot against the bar from eight yards.
The Eagles continued to push forward, but despite a succession of corners Boro's defence held firm and the away side continued their perfect away start to the season.
Crystal Palace: 1. Julian Speroni, 3. David Wright (20. Jon Williams '80), 4. Jonathan Parr (17. Glenn Murray '68), 5. Paddy McCarthy, 7. Darren Ambrose (16. Wilfried Zaha '66), 11. Sean Scannell, 15. Mile Jedinak, 19. Jermaine Easter, 21. Dean Moxey, 37. Aleksandar Tunchev, 38. Peter Ramage
Subs Not Used: 34. Lewis Price, 6. Anthony Gardner
Middlesbrough: 13. Carl Ikeme, 2. Justin Hoyte, 3. Joe Bennett, 4. Matthew Bates, 7. Scott McDonald (8. Kevin Thomson '76), 9. Marvin Emnes, 10. Nicky Bailey, 14. Rhys Williams, 17. Barry Robson, 29. Tony McMahon, 38. Faris Haroun (6. Stephen McManus '79)
Subs Not Used: 5. Merouane Zemmama, 11. Tarmo Kink, 22. Malaury Martin
Bookings: Bennett, Robson
Sent Off: Bennett
Att: 15,198 (Away: 1,692)