I think this is everything we have for Sampras:
1992 RG QF, lost to Agassi
Sampras made his first serve on 5 of 10 break points (50%). When facing break point, he won 3 of 5 on first serve (60%) and 1 of 5 on second (20%).
1993 Wimbledon QF, d. Agassi
Sampras made his first serve on 7 of 11 break points (64%). When facing break point, he won 5 of 7 on first serve (71%) and 2 of 4 on second (50%).
1993 Wimbledon final, d. Courier
Sampras made his first serve on 1 of 2 break points (50%). When facing break point, he won 0 of 1 on first serve (0%) and 0 of 1 on second (0%).
1993 USO final, d. Pioline
Sampras made his first serve on 1 of 3 first serves (33%). When facing break point, he won 0 of 1 on first serve (0%) and 1 of 2 on second (50%).
1995 AO final, lost to Agassi
Sampras made his first serve on 7 of 21 break points (33%). When facing break point, he won 5 of 7 on first serve (71%) and 11 of 14 on second (79%).
1995 USO final, d. Agassi
Sampras made his first serve on 5 of 6 break points (83%). When facing break point, he won 3 of 5 on first serve (60%) and 1 of 1 on second (100%).
1995 Davis Cup final, d. Chesnokov
Sampras made his first serve on 3 of 10 break points (30%). When facing break point, he won 2 of 3 on first serve (67%) and 3 of 7 on second serve (43%).
1995 Davis Cup final, d. Kafelnikov
Sampras made his first serve on 5 of 7 break points (71%). When facing break point, he won 3 of 5 on first serve (60%) and 2 of 2 on second (100%).
1996 AO R32, lost to Philippoussis
Sampras made his first serve on 2 of 6 break points (33%). When facing break point, he won 1 of 2 on first serve (50%) and 4 of 4 on second (100%).
1996 RG SF, lost to Kafelnikov
Sampras made his first serve on 8 of 13 break points (62%). When facing break point, he won 5 of 8 on first serve (63%) and 3 of 5 on second (60%).
1996 Wimbledon QF, lost to Krajicek
Sampras made his first serve on 2 of 5 break points (40%). When facing break point, he won 1 of 2 on first serve (50%) and 2 of 3 on second (67%).
1996 Stuttgart final, lost to Becker
Sampras made his first serve on 9 of 14 break points (64%). When facing break point, he won 8 of 9 on first serve (89%) and 2 of 5 on second (40%).
1996 Masters Cup RR, lost to Becker
Sampras made his first serve on 2 of 3 break points (67%). When facing break point, he won 1 of 2 on first serve (50%) and 1 of 1 on second (100%).
1996 Masters Cup final, d. Becker
Sampras made his first serve on 3 of 5 break points (60%). When facing break point, he won 3 of 3 on first serve (100%) and 1 of 2 on second (50%).
1998 USO SF, lost to Rafter
Sampras made his first serve on 4 of 6 break points (67%). When facing break point, he won 2 of 4 on first serve (50%) and 0 of 2 on second (0%).
2001 AO SF, lost to Agassi
Sampras made his first serve on 10 of 13 break points (77%). When facing break point, he won 9 of 10 on first serve (90%) and 1 of 3 on second (33%).
2001 Wimbledon R16, lost to Federer
Sampras made his first serve on 10 of 14 break points (71%). When facing break point, he won 8 of 10 on first serve (80%) and 3 of 4 on second (75%).
2001 USO final, lost to Hewitt
Sampras made his first serve on 7 of 13 break points (54%). When facing break point, he won 5 of 7 on first serve (71%) and 2 of 6 on second (33%).
2002 USO final, d. Agassi
Sampras made his first serve on 6 of 12 break points (50%). When facing break point, he won 6 of 6 on first serve (100%) and 4 of 6 on second (67%).
All break points saved:
1990 USO final, d. Agassi
Sampras made his first serve on 1 of 3 break points (33%).
1993 Wimbledon SF, d. Becker
Sampras made his first serve on 4 of 6 break points (67%).
1994 Wimbledon final, d. Ivanisevic
Sampras made his first serve on 2 of 2 break points (100%).
1997 Wimbledon final, d. Pioline
Sampras made his first serve on 0 of 1 break point.
1997 Grand Slam Cup final, d. Rafter
Sampras made his first serve on the only break point he faced.
1999 Wimbledon final, d. Agassi
Sampras made his first serve on 4 of 4 break points (100%).
2000 Wimbledon final, d. Rafter
Sampras made his first serve on 1 of 2 break points (50%).
2001 USO QF, d. Agassi
Sampras made his first serve on 2 of 3 break points (67%).
Outstanding stat for Sampras at '95 AO.