I'm a (very) amateur player and have seen the use of en-passant only a couple of times in club games. Chess books I've read (Soltis, Weeramantry, Pandolfini,etc.) feature hardly any games having en-passant pawn captures.
Are there any recent championship games featuring a serious use of en-passant?
By "serious" I mean the outcome of the game depended substantially on this move.
I'll give an example that isn't from a world championship match, and isn't recent either. In fact, it doesn't even have an en passant capture in it. (Bear with me.) It does have a world champion playing in it, though, and more importantly, I hope it illustrates the following: even when no en passant capture actually occurs in a game, the fact that it is possible might be playing a very big role. This is not entirely unrelated to the old chess saying, "the threat is stronger than the execution."
In the game Alekhine - Yates (London 1922), we have the following position after black's thirty-first move:
[FEN "r3r1k1/2R3p1/2R1p2p/3pNp1P/p2P1K2/Pp2PP2/1P4P1/5b2 w - - 0 31"]
1. g3 1... Ba6 (1... g5+ 2. hxg6) 2. Rf7 Kh7 3. Rcc7 Rg8 4. Nd7 Kh8 5. Nf6 Rgf8 6. Rxg7! Rxf6 7. Ke5 7... 1-0 (7... Rff8 8. Rh7+ Kg8 9. Rcg7#) (7... Raf8 8. Rh7+ Kg8 9. Rcg7#)
Alekhine has boldly played his king forward with the idea of infiltrating the black position via e5. On the previous move, Yates had attacked his g-pawn with 31. ... Bf1 and Alekhine replies simply with 32. g3 to keep the pawn safe, ready to get back to business after that. Looking at the position, we can see that if Alekhine didn't have the en passant capture at his disposal, then Yates would be able to checkmate him with 32. ... g5. But since the rule is in effect, Alekhine's king is actually perfectly safe, and in a strong position to help his other forces attack.
Now Alekhine didn't have to play 32. g3 setting up this "pseudo-mate" possibility. But still the point is that the white pawn on h5 and its en passant threat plays a big part in Alekhine's suffocating clamp on the black position, and his successful invasion. Yates resigned only a few moves later, with Alekhine's king delivering the final blow on e5: 32. ... Ba6 33. Rf7 Kh7 34. Rcc7 Rg8 35. Nd7 Kh8 36. Nf6 Rgf8 37. Rxg7! Rxf6 38. Ke5 1-0.
Yates must lose his rook, because if either rook moves to f8, Alekhine has mate in two with 39. Rh7+ Kg8 40. Rcg7#. To reiterate the larger point:
Many potential en passant captures that never actually occur, because the mere possibility of it discourages the other player from ever making the two-square advance in the first place, still play a major role in the game. This aspect - the most effective en passant is perhaps the one you never see - is one reason why, superficially, the en passant capture might seem like a less important/significant feature of chess than it actually is.
In 12th (Final) game of Anand - Topalov match, en passant did come into play.
Position after 36...g5+
37. fxg6 is an en passant capture. Topalov still lost the game; however, if he did not have en passant capture, he would've lost much sooner.
[FEN ""]
[Event "World Championship Match"]
[Site "Sofia BUL"]
[Date "2010.05.11"]
[EventDate "2010.04.26"]
[Round "12"]
[Result "0-1"]
[White "Topalov"]
[Black "Anand"]
[ECO "D56"]
[WhiteElo "2805"]
[BlackElo "2787"]
1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.Nc3 Be7 5.Bg5 h6 6.Bh4 O-O 7.e3
Ne4 8.Bxe7 Qxe7 9.Rc1 c6 10.Be2 Nxc3 11.Rxc3 dxc4 12.Bxc4 Nd7
13.O-O b6 14.Bd3 c5 15.Be4 Rb8 16.Qc2 Nf6 17.dxc5 Nxe4 18.Qxe4
bxc5 19.Qc2 Bb7 20.Nd2 Rfd8 21.f3 Ba6 22.Rf2 Rd7 23.g3 Rbd8
24.Kg2 Bd3 25.Qc1 Ba6 26.Ra3 Bb7 27.Nb3 Rc7 28.Na5 Ba8 29.Nc4
e5 30.e4 f5 31.exf5 e4 32.fxe4 Qxe4+ 33.Kh3 Rd4 34.Ne3 Qe8
35.g4 h5 36.Kh4 g5+ 37.fxg6 Qxg6 38.Qf1 Rxg4+ 39.Kh3 Re7
40.Rf8+ Kg7 41.Nf5+ Kh7 42.Rg3 Rxg3+ 43.hxg3 Qg4+ 44.Kh2 Re2+
45.Kg1 Rg2+ 46.Qxg2 Bxg2 47.Kxg2 Qe2+ 48.Kh3 c4 49.a4 a5
50.Rf6 Kg8 51.Nh6+ Kg7 52.Rb6 Qe4 53.Kh2 Kh7 54.Rd6 Qe5 55.Nf7
Qxb2+ 56.Kh3 Qg7 0-1
Source: http://www.chessgames.com/perl/chessgame?gid=1582125
