Thank you all for the replies. I actually did think (of rather feel) that a game could be won on fuseki+early middlegame. Maybe because of reading in commented games statements like "the game is essentially over.". I should have understood it meant "the game is over if the player that's ahead, plays at his top level for the remainder of it and doesn't make any major mistakes".
I did finally win this game, but around move 80 I think I was ahead and a few moves later I wasn't so sure I'd win the game anymore. I'm playing a 5H game at the moment, that I'm starting to think I'll lose, and it will be a better example than this one.

(First time I attach a game, I hope it works)
(
;FF[4]GM[1]
AP[DGS:1.0.15]
PC[Dragon Go Server:
http://www.dragongoserver.net/]
DT[2012-08-06,2012-08-08]
GN[nnnnnnn-Alguien-750151-20120808]
PB[Alguien (Alguien)]
PW[N (nnnnnnn)]
BR[5k]
WR[6k]
XM[204]
GC[Game ID: 750151
Game Type: GO (1:1)
Rated: Y
White Start Rating: 5k (-49%) - ELO 1551
Black Start Rating: 5k (-23%) - ELO 1577
White End Rating: 6k (+27%) - ELO 1527
Black End Rating: 5k (+13%) - ELO 1612]
OT[30 days with 1 day extra per move]
RU[Japanese]
SZ[19]
KM[6.5]
RE[B+Resign]
;B[pd]
;W[dp]C[[Ignore this. Testing Eidogo\]]
;B[pq]
;W[dd]
;B[qk]
;W[nc]
;B[pf]
;W[jd]
;B[fq]
;W[hq]
;B[cq]
;W[cp]
;B[dq]
;W[ep]
;B[fr]
;W[go]
;B[cj]
;W[cl]
;B[cf]
;W[cd]
;B[ef]
;W[gc]
;B[kp]
;W[po]
;B[np]
;W[qq]
;B[qr]
;W[qp]
;B[rr]
;W[qm]
;B[nn]
;W[om]
;B[on]
;W[pn]
;B[pl]
;W[pm]
;B[rl]
;W[rm]
;B[mk]
;W[nm]
;B[mn]
;W[nk]
;B[oj]
;W[nj]
;B[oi]
;W[jq]
;B[kq]
;W[ok]
;B[fd]
;W[fc]
;B[me]
;W[md]
;B[le]
;W[mh]
;B[ni]
;W[mj]
;B[mi]
;W[lj]
;B[ek]
;W[qc]
;B[qd]
;W[pc]
;B[od]
;W[oc]
;B[en]
;W[em]
;B[fo]
;W[fp]
;B[gn]
;W[ho]
;B[fm]
;W[dm]
;B[hn]
;W[io]
;B[ji]
;W[he]
;B[ed]
;W[ec]
;B[hg]
;W[li]
;B[lh]
;W[be]
;B[bp]
;W[bo]
;B[bq]
;W[bj]
;B[bi]
;W[ci]
;B[dj]
;W[bh]
;B[di]
;W[ch]
;B[bn]
;W[ao]
;B[cn]
;W[dn]
;B[co]
;W[do]
;B[dg]
;W[bk]
;B[ll]
;W[jj]
;B[ij]
;W[ii]
;B[jh]
;W[jk]
;B[ik]
;W[il]
;B[hl]
;W[fl]
;B[el]
;W[gg]
;B[hf]
;W[gf]
;B[gh]
;W[fh]
;B[fg]
;W[hh]
;B[gi]
;W[hk]
;B[hj]
;W[dh]
;B[eh]
;W[gk]
;B[ih]
;W[hm]
;B[im]
;W[gl]
;B[jl]
;W[kl]
;B[jm]
;W[gm]
;B[in]
;W[fn]
;B[kj]
;W[kk]
;B[fm]
;W[kn]
;B[km]
;W[lk]
;B[fn]
;W[lm]
;B[ln]
;W[mm]
;B[ko]
;W[rc]
;B[rd]
;W[sd]
;B[se]
;W[sc]
;B[rf]
;W[gd]
;B[kd]
;W[kc]
;B[ld]
;W[lc]
;B[je]
;W[ie]
;B[jf]
;W[ff]
;B[fi]
;W[nd]
;B[ne]
;W[bm]
;B[an]
;W[jr]
;B[kr]
;W[ks]
;B[ls]
;W[js]
;B[lr]
;W[pk]
;B[qj]
;W[ql]
;B[id]
;W[jc]
;B[ge]
;W[pj]
;B[pi]
;W[qi]
;B[ri]
;W[qh]
;B[rh]
;W[kh]
;B[lg]
;W[mg]
;B[qg]
;W[kg]
;B[lf]
;W[fe]
;B[ee]
;W[ge]
;B[jp]
;W[bf]
;B[bg]
;W[ag]
;B[cg]
;W[ai]
;B[gq]
;W[gp]
;B[ip]
;W[hp]
;B[iq]
;W[]
C[Result: B+Resign]
)